Anyway, its very hard/impossible to explain with words so the best thing to do is to download some of the video tutorials from 3dbuzz.com or 3dpalace.com
They both have uvw unwrapping tutorials as far as I know.
Thanks to malward, was trying this out yesterday. works pretty well for plain objects. but if you were trying to unwrap a face, or a section of a character than curves at the top and joins, say at the section at the top of the face, then you will have to change the area about a bit and give it more of a perpendicular edge. it works quite well actually :D
use spatial model aswell in the reactor cloth settings for fold stiffness.