If you have never heard of LXDE, you probably are not alone. It is, however, a very nice lightweight desktop environment and certainly worth trying if you are building a lightweight Linux system. I have already written a positive review of LXDE some time ago, you'll find more information and screenshots in my review.
Those of you who already are using LXDE might be interested in the LXDE blog. It's full of interesting reading for anyone using LXDE.
If you have problems with LXDE, the best place for getting support is the new LXDE Forum. It does not yet have many posts, but that will probably change soon as LXDE becomes more popular.