This is a good article from Knitty.
http://www.knitty.com/ISSUEwinter04/...bynumbers.html
Jarod Flood (Brooklyn Tweed) also had a couple of good articles in Vogue Knitting about a year ago on how to adapt a regular pattern so that it could be knit in the round. (Fall 2009 and Holiday 2009) Hope this helps.