I've put together a video screencast introducing the concept of HDR, what it means and how you could use it.
So the essence of a (potentially) great HDR landscape shot is an interesting sky, well composed image, a very still camera, and at least 3 photos taken at different exposure values, one just right, then two others at + or - 1 ev (or more).
You can get a trial version of the Photomatix HDR software at hdrsoft.
I've done quite a few HDR's now, and you can see them in my Flickr set on HDR.
Thanks for reading / watching and enjoy your HDRing!