Get the beta version of Lightroom 3 right now for free by downloading it. That will get you up to speed with it when the full version comes out. There are lots of tutorials on it around the web.
The best source I've found for good honest used equipment is fredmiranda.com in the buy/sell forum. Sellers have ratings and they are good pros there that are very knowledgeable. Listen to Wapiti hunter...a cheap dslr with L series lenses will make National Geographic type images. A nice camera with crap lenses won't.
I have also found good gear on craigslist. Part of that is knowing what you are buying and testing it out before you buy which you can do in person. Before buying a camera, make sure you know how to figure out how many actuations it's had. Something less than 20k would be desireable.