I found this link particularly helpful when learning to do a one-handed roll:
http://www.drummagazine.com/html/mod...rticle&sid=650
Of course, I still haven't perfected my technique yet, as it's difficult to learn from a print source. I'm looking forward to checking out the video link that AvengedDrummer posted, because I think that will help me way more. It's much easier to watch someone than it is to try to figure it out alone. And the videos I've found aren't particularly helpful; just people showing off instead of giving actual information.