Digital Camera Resource Page--an excellent all-around place to learn about digital cameras, especially in its well-organized message boards. Of special note: the "Where should I buy my camera?" board, where you'll find out which dealers are sleazy and which ones are good! (As with all bulletin board systems, read the recent messages to see whether your question has already been answered before posting.)
Imaging Resource--notable for its extremely detailed reviews
Short Courses--publisher of excellent books on digital photography and on particular brands and models. Highly recommended! Much of their material is also available on their website, so you can read it online and decide whether to buy the book.
Steve's Digicams--another general digital photography site. Notable for its "Breaking News" feature, updated daily. But take Steve's reviews with a large grain of salt--he rarely says anything bad about a product!
The Luminous Landscape--devoted to fine-art photography with digital equipment
Digital Camera Resource Page Reviews & Info--well-laid-out feature comparison chart of all popular brands and models, with links to detailed specs, reviews and lowest prices
Imaging Resource Reviews--incredibly thorough, detailed reviews--teach you more than the owner's manual!
Maha charger review--highly recommended charger for NiCd and NiMH batteries is reviewed by Steve's Digicams
B&H Photo-Video, one of the oldest and most reputable dealers in the field, and a favorite of the pros.
J&R Computer World/J&R Music World another thoroughly reliable dealer that I've been buying from for thirty years or more.
Norman Camera--Excellent support from this Kalamazoo-based dealer; I bought my last two cameras there.
My Battery page--everything you need to know about AA batteries and digital cameras--what kinds to buy, what kinds to avoid, where to get 'em cheaply
CKC Power auxiliary lenses and specially made accessories for digital cameras from Olympus, Nikon and Kodak that have filter threads
Nixvue Digital Albums--affordable multigigabyte storage devices for archiving photos when in the field
Buy.com--excellent prices on digital cameras, photo printers and accessories such as ink cartridges and paper
Porter's Camera Store--every kind of photo accessory imaginable, including tripods, flashes, etc. They also sell digital cameras, but their prices are sky-high--don't buy your camera here.
Thomas Distributing--great place to buy rechargeable batteries and chargers