I second the recommendation to start out on the older manual focus cameras. At least until you've developed the basics and determine whether or not the investment of $$$s is worth it for the newer autofocus everything slrs. This is especially true on a budget as lenses are far cheaper that the autos. Your initial investment "shouldn't" be much more than $100 bucks. simi auto exposure models from the early 70s are also very nice and convenient with shutter/aperature priority settings. Some camera's that I have heard recommendations ...
Canon AE-1, A-1.
Pentax K1000, Spotmatics
Nikon FG, FG-20, and although more expensive FE series.
Highly recommend finding a camera show if there are any in your area. Talk, learn, chit chat, and deal.
I'm liking my spotmatics and their m42 lenses from various makers. Just bought a 28mm f2.8 for $5 at a camera show. I also like my Pentax Kmount ME SE but it only operates in aperature priority with +-2x exposure compensation.