People often ask me where I get my information on stoves. Well, a lot of my information comes from my life. I own over 100 backpacking stoves (hey, some people collect stamps, why not stoves?), and I use them. I use my stoves pretty much every week on day and overnight hikes, and in most weeks, I'll be out hiking more than once a week. I also meet people on the trail, hike with the Sierra Club, talk with friends, etc. Between using stoves and talking with others who use stoves, I pick up a lot of information.
BUT, there are some good web sites with really good information on them. Some of the sites I refer to regularly include:
Classic Camp Stoves -- All the information you could ever want on classic and antique stoves as well as plenty on modern stoves. Don't know what that old stove in grandpa's garage is? Find out here. An amazing resource.
wikipedia.com -- Wikipedia has good information on the properties of gases and fuels
zenstoves.net -- The grand daddy compendium of stove web sites
The Confederation of Bushwalking Clubs NSW Inc Web Site -- They have an excellent FAQ
BackpackingLight.com -- They have excellent articles and excellent forums. Paid membership required for most articles.