seriously consider renting some gear to try out options before you buy. Places like borrowlenses.com are great for letting you check out options without a strong commitment. Canon/Nikon is to a good degree a religious argument, I recommend you figure out which most of your friends use and then think about joining them; they'll be able to help you learn the gear, and you can probably borrow lenses from them to try out as well.
The recommendation to think about and focus on lenses is right on. The way technology is going, it's not unusual to be upgrading bodies every few years as your skill progresses; but lenses you buy now will be with you for a decade or more. When I started building my collection, I spent on a key lens, bought an inexpensive lens to supplemnt it, and went with a lower end body. Since then, I've added a couple of lenses, upgraded my inexpensive lens, and upgraded my body twice -- but the key lenses are going to be with me for a long time. So put your money in to the best glass you can, and it'll serve you well.
My purchase history (over four years)
Canon kit wide angle lens
Canon Rebel XT
Added: Canon 300/F4
Added: Canon 30d body
Added: Sigma 180 Macro
Added: Canon 1.4x teleconverter
Added: Tamron 28-300 (retired Canon Kit lens)
Added: Canon 7d (retired Rebel XT)
also bought a 480EX flash, added a 580EX, then bought a used 580EX II and retired the 480EX.
I've spent fairly heavily on top quality lenses, except for the wide angle where I decided go less expensive (I wanted a flexible street lens that would work as a one-body/one-lens pack for urban shooting that was small and light). In retrospect, I would buy the sigma 18-200 instead of the tamron -- I prefer the build quality of sigma over tamron, and the tamron isn't wide enough at the low end so I'm always fighitng it to get the shot I want, and the extra zoom at the top end doesn't really benefit me as much as I thought it would (more on this here: http://www.chuqui.com/2010/01/a-few-thoughts-on-lenses/ ). When I do upgrade my wide angle, I'll probably buy much wider and with less zoom, probably a high quality Canon like the 17-55 F2.8 IS (but the 17-50 F2.8 looks tempting and is much cheaper).
My current buying plans include another 7D and the wide angle lens. Then I'm going to start saving up for a 500mm....