While I've never been in a jail for something i did, I took a tour of Alcatraz in San Francisco.
A lot of it was corridors with multiple cells on top if each other. Search the Models and Media thread for jail, I think it was Higgins who posted free jail bar entities.
heres a picture of a cell.
http://en.wikipedia.org/wiki/Image:Alcatraz_cell.JPG
If you have the game Dead to Rights, you get sent to a prison in that game. Thats kind of what Alcatraz looked like. If you don't have the game, you can buy it for about $5 off Ebay. Not only would it help you with your game, but it was a lot of fun to play.
Other parts of prisons would be a large room with many tables, serving as the Mess Hall. Theres also Storage Rooms, with boxes. Offices, with desks, paperwork ect. Then theres also weapon storerooms. Most prisons have a "Rec Room" which is a room with weights and other gym equipment, unless I'm mistaken someone recently made a free pack of gym equipment. You also should take infirmaries into account.
My advice, buy "Dead to Rights" and "The Chronicles of Riddick: Escape from Butcher Bay". They both show the insides of prisons, and let you run around in them. While the Riddick game is not a modern prison, it might give you some good ideas.
"I admire its purity, a survivor, unclouded by conscience, remorse, or delusions of morality"
