Before you go any further, I assume you have a place where you can get film developed, and you are aware of the costs of film and developing, as well as prints and/or scans in your area, and I assume that you do want to use film. Beginning with digital is a slightly different beast, and the comments below are in reference to beginning with a film camera, which, despite my pro-digital outlook, I consider a good idea.
Basically, regardless of the style of camera (rangefinder, slr, or other), there are a couple of things you should look for. The most important is fully manual controls, where for each shot you have to (or have the option to, which you should take) set the aperture and the shutter speed yourself. Another thing to look for in a good beginner's camera is a good built in light meter. You want a camera that is in good shape, which has a good reputation for reliability. You also probably want a relatively inexpensive camera, something that can be picked up for a couple hundred bucks or (potentially much) less. This leaves you with basically two options, a fixed lens rangefinder (FLRF) or an SLR.
If you go with the FLRF route, choose carefully. Even though a lot of them have built in meters, a lot of them don't meter in manual mode, which is what you want to use. The Olympus 35 SP fixed lens rangefinders are probably the best choices for your needs, since they can meter in manual mode. Don't worry about the inability to change the lens. For the first year or two at least, all you really need is a reasonably fast lens of a normal focal length, which is what the FLRF's have.
If you choose an SLR, you have loads and loads of choices. My top recommendation for someone who is just starting out is the venerable Pentax K1000. It was designed as a simple, rugged student camera. It does everything a beginner needs it to do and it doesn't do anything else. Pair it with a 50mm lens, either pentax or ricoh, and you can be out there shooting with a reliable rig for 100 bucks or less. If you go this route, don't get a zoom lens. Again, all you need until you gain a firm grasp on photography is a prime lens of a normal focal length. IMO, for a beginner, a zoom lens is almost as bad as using program mode.
Don't use an RF just because your hero or heroes used them. At the time when HCB was making some of his best work, an RF was pretty much the only game in town. There are loads of great reasons to use an RF camera, but that isn't one of them.
See if a local college or university offers photography classes that you would be able to take. That would be an invaluable experience for you. Most college and university intro to photography classes require fully manual SLR cameras, so keep that in mind if you do consider that option, which I highly recommend.
The only good way to learn photography, IMO, is to use fully manual controls, and to use fully manual controls for a long time. I started using non-manual controls far too early, my photography suffered, and I found myself not doing any photography for several years because of it. It is only recently that I have started using either aperture priority or shutter priority (never program AE) again, and that is only because I have a firm grasp on my principles and concepts.
I recommend a camera with an accurate internal meter for a couple of reasons. First, simplicity. Having an external meter is one more thing to keep up with and worry about, and when starting out, you have a lot to juggle in your brain anyway. Second, I think that the fact that you can see the exposure meter change as you adjust the settings is a useful visual demostration of the effects you are having on the exposure.
Another big recommendation that I give to beginners is to get a decent tripod, and practically (not literally) glue your camera to it. Using a tripod allows you to take a bit more time with your shots, make sure your composition is good, as well as lined up just like you want, and it gives you more time to check your focus. I know you like the fast and freewheeling style of HCB, but you can't do something fast and well until you can do it slowly and well first. Concentrate on becoming a good photographer before you worry about being able to make good images speedily. For me, using a tripod when you start out is a lot like using manual controls. I only very rarely use a tripod any more, but I am a better photographer for having used one for years. The key reason to use a tripod is that it makes you think more about your composition. Bresson didn't use one (at least I have never seen reference to him using one), but he was a draftsman (and painter?) before he took up photogaphy, so he learned composition that way. For someone who doesn't come from that kind of fine arts background, a tripod and some design theory are the next best thing.
Good luck!
