$500. My advice is to stay with Canon, and get the best medium range zoom that you can afford. I would aim for L lenses, although I realize that they are costly. Then save your money for additional and/or better lenses. I just talked to a bunch of working pros last night. They said to stick with Canon or Nikon. They are both good. Anything else isn't.
I use the Sandisk Extreme III 1gig with the 20D. It is fast enough that the camera doesn't seem to be slowed down by it. I always shoot raw unless I'm running short on space.
Also, look for a portable harddrive with a built in card reader. You'll be surprised how fast those cards fill up. When I'm traveling, I usually have a portable computer that can burn a second copy of the images to CD.
I have no experience with photo books, but there are all kinds of services around these days.
I am looking for the best sub $500:
a.) 17-70mm lenses ? Sigma F2.8-4.5
b.) 20 to 30mm prime lense ?1.4
c.) 70 or 100 to 300mm telephoto lense
to go with a Canon 20D.
The best flash cards (Compact flash) Sandisk or Lexar?
The best place to get Photo books made for major trips and events from my photos?