High Dynamic Range Photography (HDR) is performed by taking two or more different exposures of the same scene and merging the photos to create a unique looking, evenly exposed photograph. Wikipedia defines HDR as a set of techniques that allow a greater dynamic range of luminance between the lightest and darkest areas of an image than current standard digital imaging techniques or photographic methods.
The main process is to set your camera to bracket your shots (my Nikon D90 brackets 3 shots). The bracket includes one regular + one underexposed + one overexposed shot. A tripod is pretty much required, unless you have a really stable surface to sit yout camera on. I then take the three shots and merge/process them in PhotoMatix Pro. I am sure, I am not doing everything correctly, but I like what I see so far. There is a lot still to learn. Below I have listed some of the resources that I have run across online.
Tutorials and Resources
“There is only you and your camera. The limitations in your photography are in yourself, for what we see is what we are.” - Ernst Haas