I use a Canon 7D now, after having a Canon 40D. I have only two lenses that I use regularly, a telephoto and a 60mm macro f 2.8.

I met a pro once who told me three somewhat simple tips: 1. Use a tripod whenever you can, as you aren't as steady as you might think, 2. Shoot RAW as you can do a lot more with it, 3. Use Lynda to learn stuff. He felt that the other avenues of typical learning weren't as good, such as workshops or magazines (for the average amateur). I realize carrying your camera, and shooting a lot of photos - experimenting, is another great idea. I don't carry mine enough.

In response to in-camera vs. post-production... I try to get the best CAPTURE with the camera, and then do whatever editing afterwards from the RAW file, assuming the photo is to my liking. I think most DSLRs will do some sort of sharpening, saturation, etc. in the camera, but I've stayed away from them. I am constantly learning more about the effective use of layers in Photoshop for editing, like sharpening.

I also agree with Barwaut that it's hard to take interesting photos of cars. I like that challenge, and wonder if any of my car photos would appeal to a non car nut.