S.L. Viehl talks a bit about descriptions in writing. For the most part, I hate long-winded descriptions and would much rather write dialog or action; my general approach is to "fold" the descriptive stuff into actual action; instead of saying, "Gwyn had unruly, auburn hair", I'm more likely to write something like "Gwyn brushed a lock of auburn hair from her eyes". And then, I can have her do this every once in a while, thus not only establishing the color and quality of her hair, but giving her a habitual action that makes her a bit more vivid.
Of course, when writing my first draft -- the "closed-door draft" that Stephen King talks about -- I tend to throw in all manner of long, descriptive paragraphs, and I'm finding that in the course of editing I'm removing great whacks of that stuff. I figure, if I'm skipping over that stuff in my own writing, then I'm not going to be doing my readers (theoretical entities as they are at this point) any favors by leaving it in.
It takes a very good author, someone well-schooled in what to do with language, to make long passages of description interesting. This is probably where reading a lot of poetry comes in handy.