In your situation, I'd advise buying a used one until you really become familiar with different models and know what features will be most important to you.

A Pentax K1000 is very basic but excellent camera to learn on. It's all manual, so you are forced to become familiar and competent in all areas of metering and focusing.

Here's an article which may give you more information on manual SLRs:

http://shutterbug.com/equipmentreviews/35mm_cameras/0201sb_allmanual/

When you become really proficient, then you can go for what the big boys buy in 35mm: Nikon F6. It's the ultimate. A friend of mine is a fashion photographer and sells to the big rags like Vogue, Playboy, Cosmo, and so forth, and he won't use anything else.