This page is out of date, but is retained for archival purposes.
Here are the choices and tradeoffs:
While it may be the most expensive option, a good store with trustworthy staff can help you find the right camera for your needs and keep you from making a mistake. There are also local stores whose staff are ill-informed, misleading, and more interested in a profit than in your needs, but they do not last long in these days when online stores are so accessible.
Ask your photographer friends for a good recommendation.
Discount retailers such as Circuit City, Best Buy, CompUSA, and Walmart offer good prices, especially if you can catch a promotion or sale. Be skeptical of any advice they offer. Sometimes they get good sales people, but just as often the people are learning on the job. Do your homework and trust yourself when going here. Do NOT buy camera memory here. It is much cheaper on the web.
The best buys are usually online, especially for camera memory. But some offers are too good to be true.
How do you know which to patronize and which to avoid?
The most reputable camera store on the web is http://www.bhphotovideo.com. This New York camera store has a great reputation on and off the web. (Most NY and NJ discount camera stores have poor reputations.)
Reputable electronics stores are also good choices. I regularly use buy.com and Amazon.com.