I use a Canon (not Cannon) 10D (SLR) and love it. I also have a Canon S500 SureShot pocket digicam, which works well when I don't want to carry the Canon. I've used Nikon and Kodak products before. A couple of comments to add to the very good discussion above:
Canon's range of lenses is somewhat different from Nikon's, and many think better overall (some don't; Nikon certainly makes wonderful optics). The Nikon-Canon debate is endless; perhaps just try them in a store and pick what feels right. Your mileage may vary, as they way. They both seem to have some ho-hum consumer lenses and some real gems, plus great glass as you move up the price list. Canon seems to be ahead in range of telephotos and image stabilization. Nikon maybe has better choice of wide angle lenses. But only Canon makes a full-frame digital SLR, and, at any digital SLR level, Canon's low-light (high ISO) performance is much superior -- way less noise (think "digital grain"). I've often heard pros say you are really buying a lens system, not just a camera.
All Canon "EF" lenses work with current and recent former Canon SLRs, except the "EF-S" lenses which work only on the more recent, APS-C sensor digital SLRs such as the 30D, 20D, and digital Rebel (300D etc.) and not on any full-frame camera. The older Canon lenses (such as "FD") do NOT work on any Canon digital SLR (at least, not without a clunky adapter arrangement). I use a film EOS 5 (European AE2) as well as the 10D. Many think Canon will announce one or more new camera(s) during the next week or so at Photokina. Early reports on the recently-announced 400D seem good; 10 megapixels and includes sensor cleaning, too!
Many Canon digital SLRs use a polycarbonate body that is extremely strong, with a metal chasis. No need to have the entire camera be metal, which adds much weight.
Newer Canon image stabilized ("IS") lenses do work on a tripod without turning the IS off.
About megapixels: SLRs generally have much larger sensors than digicams. As a result, the same number of pixels in an SLR does a much better job than a digicam. Also, if thinking of a digicam with zoom, remember that only the optical zoom counts. Digital zoom simply takes the same pixels and looks closer at them -- just like using a magnifier on a newspaper photo, you start see1ing the little dots pretty soon. You can use your favorite image processing program on your computer to do the "digital zooming" later, if you want (with pretty much the same image quality issues).
I'd recommend www.photo.net for further information -- a very good site run out of M.I.T. and used by many from very new to very experienced photogs. Another one I like is http://luminous-landscape.com/ (no "www"); www.dpreview.com is very popular. Interesting stuff at www.bobatkins.com. Good light and good shooting!
