The above post covers most of the important factors in police officer recruitment. If you want good, spot-on information for a police academy, check with your municipality's website, or you can check with your state's government employment directory either at your revenue office or online. The standards vary from city to city, from county to county, and from state to state.
If you're writing a police academy scenario into your story, I recommend doing some research on the various types of law enforcement organizations that could fit into your story. You have your pick among federal agencies, paramilitary groups, intelligence agencies, and local offices. Of course, if you're posting this topic, I can assume you already know this by now. Just make sure you don't have heavily armed government agents doing low-level patrol duty, or vice versa, local police officers hunting high-value suspects outside of their jurisdiction. It seems obvious, but a lot of novels and television shows don't properly portray the kind of training officers need for their respective roles.
Many hiring agencies require applicants to take both an entry and exit exam within a 3 to 4-year period, both written and physical. In some jurisdictions, a person applying for law enforcement with prior experience working for a municipality or state government can receive expedient approval from a certified supervisor.
I also suggest doing research on training programs used by various nations. Some countries have more militaristic training programs than others, and in some cases, the police academy and military basic training can even overlap for qualifying citizens.
Edit: 26 weeks sounds short, but it really isn't. Most citizens train nights and weekends while tending to their day jobs and family responsibilities, so it's a bit stretched out. Also bear in mind that after graduating from a police academy, an officer is typically placed under a probationary status for roughly 2 or 3 years before they can patrol and investigate under a fully operational capacity. During the probationary period, an officer will be supervised by a veteran who will submit monthly progress reports until the satisfactory patrol requirements have been met.
edited 29th Nov '10 9:37:44 PM by Aprilla