Well, if you want a digital camera you will definitely need more money. You can get a used entry level DSLR for about $250-300 for just the camera body. To get a starter lens, you will need another $50-100. So it could range from $300-400.
Now, if you are willing to start with 35mm, then you could get an SLR with at least one lens for $150 give or take $50. The thing is to do some research and make sure that the camera you get will work with the newer lenses for the brand so you can carry that equipment over when you go digital.
Craigslist and ebay are great places to find a used 35mm SLR, or a DSLR.
As for research, wikipedia is surprisingly accurate when it comes to cameras and photography. You could use it and type in the differene brand names and learn about the brand and the mount. For digital, dpreview.com is a great place to research.
You really can't go wrong with an SLR-film or digital. They are all capable of great images. So I would say to go to a store and try the cameras out. See which one you like.
