Hello Mr Jack, welcome to TPF!
The way to start is pretty much agreed here: Get an SLR with fully manual capability and a 50mm standard lens. It can be either new expensive and digital, or very cheap, second-hand and 35mm film. Both have pros and cons, but film is an ideal way to start as you can back out without losing much cash.
The entry level digital SLR cameras which many would recommend are the Nikon D50 and the Canon EOS350D.
As for film cameras there are literally hundreds of good models/brands to choose from.
With both of the above, I recommend getting a 50mm f1.8 fixed lens. It's flexible, easy to operate and see through and doesn't confuse.
For 35mm film cameras, I would say consider the following:
Nikon FM2a, FM3a or anything beginning F, Nikkormat
Canon AE-1
Pentax K-1000, Spotmatic
Olympus OM series
Rob