www.rattiusmaximus.com and http://www.ratzrealm.com/ would be the best sites to go to for rat info.

It's best to get 2 rats, and even better to get 3, as they require a buddy for their psycological well-being. If you kept a rat alone, you'd have to spend around 80% of your day being with that rat. They get incredibly lonely and depressed if they don't have another to "talk" to I currently have 15 girls and 10 boys. I have one boy who came from Ratz Realm.

You'd need:
-A good-sized wire cage(Super Pet makes good powder-coated wire cages with plastic bottoms and levels that work well for rats).
-Aspen bedding, carefresh, cell-sorb bedding. NO pine or cedar, the phenols will slowly kill them via lung disease/liver and kidney failure.
-Good-sized water bottle(16oz or more), they drink alot.
-ceramic food bowl
-hammocks
-Food mix(Look on the Feeder forum, and find a Sticky called Becky's Rat Food Mix). This is what I feed my rats(it's varied a bit everytime I make it), and what my other rat-owning friends feed theirs. It's cheaper and is a balanced diet, unlike the store bought crapola that has tons of seeds, alfalfa pellets(that they can't digest anyway) and dried corn. Make sure you get a GOOD dog food such as Wellness Senior, Nutro Ultra Senior, Eukanuba Senior,etc. Any good dog food with no by-products, preservatives. I personally use the Wellness as the rats actually eat it. It has awesome levels of Omega 3 fatty acids and fish oil, so it helps their skin immensely. Find a dog food with less than 18% protein and you should be good to go.
-Toys, toys, toys. They can't get enough of them. Kleenex boxes stuffed with paper towels, or shredded paper, paper towel rolls, parrot toys with bells and rawhide, in-shell nuts(walnuts, pecans, hazelnuts, etc). Just have fun with it, but be safe. None of those dried corn on the cob deals, but popcorn is ok.

That should be about it! Hope that helps