Internet Review Sites
The following sites have a good selection of reviews of many cameras and do a good job of testing:
Digital Photography Review
Digital Camera Resource Page
Fred Miranda User Reviews SLR Lenses
Photodo Objective MTF Lens Measurements
Stay away from sites with reviews that are trying to sell you something. Many merchants try to "disguise" their reviews as objective.
I also do not heavily depend on user reviews since it is hard to sniff out several modes that "pollute" the ratings:
Here's an example. I have run across dozens of reviews of the Nikon D2x digital camera. At the time, the camera was not even on the market! Sites like Digital Photography Review clearly tell you the camera is not on the market and only provide Nikon's data to you, but some user's and sites act as though they own one and can speak intelligently about it.
If you use these reviews, be sure to get a broad sense across many sites. If a piece of equipment is really a dog, you'll see it consistently in the reviews. Be aware that even the best piece of equipment has its detractors. Just don't take any of them as gospel. Give them something less than 30% weight in your total decision. They account for something like 10-15% of my decisions.
Great Uses for the Review Sites
I recently had a problem with an Olympus 5060 camera that I thought might be due to water intrusion into the underwater case. After searching some of the user groups, I found consistent chatter about a problem with the mode dial. Sent the camera into Olympus, and they replaced the mode dial. So, they do have the great value!