dpreview is a great site, also check out
http://www.steves-digicams.com for more reviews, and also
cnet.com,
http://photography-on-the.net/forum/index.php for more help on Canon digital cameras than you'll know what to do with, and 4 of the best online digital camera stores (I dont buy anywhere else than B&H):
http://www.bhphotovideo.com/,
http://www.beachcamera.com,
http://www.bluestripephoto.com,
http://www2.butterflyphoto.com