So your character has just died and has to adjust to the wholly new world of the afterlife. Or maybe they are still alive but for some reason (or lack thereof) visit the afterlife anyway.
But why should they be left to their own devices? They're probably confused enough as it is. It's much better for them to get a Spirit Advisor to show them the best view of The Pearly Gates, the nicest places in Nostalgia Heaven, and/or the structure of the Circles of Hell that they have (hopefully) avoided.
The trope's earliest mentions are Older Than Dirt, with Enkidu in the last tablet of The Epic of Gilgamesh journeying to the netherworld and afterwards explaining its order to his friend. However, the ultimate Trope Codifier is The Aeneid (with, unusually, another living human acting as guide).
- And Yet the Town Moves has its self-titled dual chapter follow Hotori Arashiyama, our protagonist, after she gets hit by a truck and gets into a near-fatal coma. She's then led around the Japanese afterlife by a civil servant from Heaven while she waits for her verification to go through, and is able to see how certain systems work or how she can still make contact with the living world.
- The Chronicles of Wormwood: Danny, Jesus, and Jimmy tag along with an angel escorting a soul to the afterlife to visit. It turns out just about everybody who didn't live too bad a life goes to Heaven regardless of creed or religion (including a suicide bomber who now has to take care of 72 screaming baby virgins for all eternity. Then they go to hell where sinners are forced to realize they were evil (even the insane) and deserve to be tortured forever (Hitler in particular is made to lick shit off a giant circumcised penis).
- The Sandman: One issue sees Dream getting led around the then-abandoned Hell by Lucifer as the demon kicks out the few stragglers who haven't gotten the message that perdition is over. They see a few former torture chambers, some lone monsters, and an ancient murderer convinced he deserves to suffer forever for killing hundreds of people who have long been forgotten.
- The Invader Zim fic To Hell With Gaz sees Gaz die and end up in Hell, which is based on the version in The Divine Comedy. The Devil proceeds to give her a tour through the nine circles (with her under the delusion that she doesn't belong there and she's being led to the way out), during which she suffers proxy effects of the various tortures due to her own sins, before finally being sealed in the ice of the ninth circle.
- Adventure Time: In "Together Again", Mr. Fox attempts to give one of these to Finn after he finally dies (and it's implied this is SOP for the recently deceased), but Finn is far too focused on getting to Death and reuniting with Jake to sit still.
- All Dogs Go to Heaven 2: Charlie serves as this for the recently-deceased Itchy, showing him the wonderful things Heaven has to offer. The twist is that Charlie is bored out of his skull by all of it—as a Lovable Rogue, being in a place where everyone is perpetually cheerful and pleasant is a Hell of a Heaven for him.
- An executive dies and is sent to Saint Paul. Saint Paul tells him that he's permitted to choose between Heaven and Hell. The exec asks if he can try them each out for a day. In Heaven, he spends all day sitting on a cloud playing the harp. In Hell, he spends all day playing golf and goes to the club for drinks. He chooses to go to Hell. When he gets there, he's placed in a cubicle for the rest of eternity. "I don't get it. Yesterday we played golf all day and drank all night." The devil replies, "Yesterday was recruitment, but now you're staff." An alternate version of this joke replaces the punchline and build-up to it with "Yesterday you were a tourist, now you're an immigrant."
- A similar joke follows the Rule of Three. A man dies and is sent to Hell, where Satan explains that he can have his choice of one of three rooms to spend eternity. The first is covered in flames; the second is a pit full of spikes; and the last is a beautiful woman on her knees giving oral sex to a disgustingly ugly man. The guy eagerly chooses Room Three, and Satan says "You heard the man, you're free to go!"... and the woman leaves.
- Another "three-room" joke has the man see a room of people lit on fire, a room of people being constantly attacked by stinging insects, and a room where everyone is standing around drinking coffee while knee-deep in human feces. The guy figures the third room is the best choice and wades in. After a few minutes, a voice announces "OK, break's over, back to standing on your heads!"
- Bill Gates dies and is given the choice between Heaven and Hell. Heaven is the typical clouds-and-harps, while Hell is a gorgeous tropical island, so Gates chooses that. But when he arrives, he finds nothing but fire, brimstone, and agony. When he asks when he gets to go to the island, Satan laughs and remarks "That was the screensaver." (Or, in some variants, "That was the demonstration version.")
- The Aeneid: Aeneas, while still alive, makes a journey through the underworld under the guidance of a likewise still-living Sybil. His purpose is to speak with his deceased father, which he does, but the Sybil also shows him around the underworld in general.
- The Divine Comedy: Dante, by the prayers of his beloved and deceased Beatrice, is allowed to journey through the various regions of Hell and Purgatory (guided by the shade of Virgil) and Paradise (guided by Beatrice), meeting celebrated sinners and saints as well as some of his real-life friends and relations.
- The Epic of Gilgamesh: Like many others, this trope appears as an Unbuilt Trope. Enkidu goes into the netherworld, almost gets stuck there but is rescued, and afterwards gives Gilgamesh a detailed description of the different fates of the people he has seen. The picture is extremely bleak even compared to what Aeneas sees: unless one has at least four sons left, one is quite miserable.
- The Great Divorce: The narrator is lost and confused in Heaven until the spirit of George MacDonald takes him under his wing and explains what's going on. He shows to him the various types of souls whom their own heavenly guides try to convince to accept salvation, and explains why many still end up in Hell.
- Inferno (Larry Niven and Jerry Pournelle), a modern retelling/deconstruction of the first portion of The Divine Comedy, has the protagonist be guided through Hell by "Benny", eventually revealed to be Benito Mussolini.
- My Posthumous Adventures: Downplayed. Because Holy Burns Evil, the not-so-virtuous Anna, although her guardian angel and her saintly relatives are willing to show her around, is only able to visit two places in the outskirts of Heaven: the Students' Vale, where the new arrivals get adjusted to the afterlife, and the Crystal Plain, where her distant ancestor is waiting for her husband in case he ascends from Hell. When Anna and her angel try to fly to a region where virtuous nuns reside, Anna can't bear the grace surrounding it and has to turn back.
- Gesta Danorum: At King Hadding's marriage (which is held in winter), a mysterious old woman shows Hading fresh stalks of hemlock and asks him whether he would like to see the place where hemlock grows in winter, to which Hadding agrees. The mystery woman wraps him into her cloak and thus takes him to the underworld, where they travel through thick fog and darkness to a sunny meadow where hemlock grows. Afterwards they cross a river bearing weapons in its water to a field where two armies are fighting, and the woman explains both armies are of men who were killed in battle. Finally they stop at an unsurmountable wall; the woman kills a rooster and throws it over the wall, and immediately it is heard crowing on the other side. Then they return.
- The Golden Girls: One episode has Rose suffer a Near-Death Experience. When she wakes up, she tells the Girls that while she was unconscious, she found herself not in Heaven, but a train station on the outskirts of it (Rose is a Cloud Cuckoolander to the extreme). A dead uncle of hers arrived to explain how the station works; since he was killed by a piece of farm equipment smacking him in the face, he suffered from Elmuh Fudd Syndwome ("Wose, this is a wetuwn ticket!").
- The Good Place is essentially "Afterlife Tour: The Series." Main character Eleanor Shellstrop dies and ends up in the titular "Good Place." The first season is largely her getting to know Heaven's features and meeting her fellow Good Place residents, all while trying to hide the fact that the Powers That Be messed up—she was a terrible person and supposed to go to the "Bad Place" instead. The concept then expands with the first season finale, a Wham Episode that reveals that, in Eleanor's words, "THIS is the Bad Place!" It turns out the characters were in Hell all along as part of an experimental new torture. The rest of the series shows the heroes trying to reach the actual Good Place, and along the way, they explore everything from the depths of Hell to the offices of a literal Celestial Bureaucracy to a special "Medium Place" that was created for a single woman who neither Heaven or Hell could truly claim as their own.
- The Twilight Zone (1959): In "A Nice Place to Visit", the small-time crook Rocky Valentine dies and ends up in a gorgeous hotel room, where Pip, a jovial fellow dressed all in white, tells him that he's been assigned as his guide and personal valet. Pip shows Rocky all around Heaven, including casinos and a Hall of Records listing every human on Earth. The twist, of course, is that Rocky eventually gets bored by getting everything he wants whenever he wants it...
- Judaism: The Jewish Parable of the Long Spoons has a rabbi being given a tour of Heaven and Hell (in some versions in a dream; in others, this happens after he dies). In Hell, all the people are surrounded by delicious food but have spoons too long to bring the food to their mouths (in some versions, their arms won't bend at all). Heaven is exactly the same, but the people there feed each other. In some versions of the tale, the rabbi, despite being worthy of Heaven, chooses to go to Hell to try and teach the people there how to cooperate.
- In the Orthodox tradition, it is believed that from the third until the fortieth day after death, a departed soul is shown the different regions of Heaven and Hell.
- In The Ecclesiastical History of the English People, St. Bede recounts the story of a man from Northumbria who was shown the different regions of the afterlife by an angel before being told his was a case of It Is Not Your Time.
- In Life of St. Andrew the Fool-for-Christ, it is described how St. Andrew, while still alive, was briefly taken to Heaven as a respite from his exhausting toil and shown around by an angel. Although, as they only had two weeks, it's explicitly noted they didn't see everything: in particular, they had no time to see the abode of the Mother of God.
- Dante's Inferno: Virgil serves as Dante's guide. With each new region or circle of Hell that Dante descends into, Virgil is there to tell him of the sins that each ring encompasses, as well as some cryptic advice for Dante's quest.
- HFIL: Upon being sent to the titular area following his death, Cell is forced into being given a breakdown of what he will have to go through before the Ogres bring him to a welcome party to introduce him to the other villains who ended up in HFIL.
- One arc in minus. has minus come across an adult reading about various depictions of the afterlife. Being a Reality Warper, she offers to show him around the real afterlife. He's thoroughly unimpressed with it, since it's basically the same thing as the normal world, including homeless people, except everyone has a ghost tail instead of legs. (The implication is that minus created the afterlife, and, being a little girl, doesn't have very complex ideas about it). He says that this afterlife is all wrong, and minus asks what he thinks it should be like. Smash Cut to him being taken across the River Styx in absolute terror.
- American Dad!: In "Rapture's Delight", When Steve and Hayley are raptured, they are given a tour of their personal Heavens.
- Futurama: In "Hell Is Other Robots", the Robot Devil shows Bender the Circles of Hell, where he will be tortured one by one. It might be a little too dark for a comedy, which is probably why the Robot Devil does all this in song.