Lots of classes teach it. I've always taught it at the second level. I'm not home today and don't have a copy with me, but I believe it's illustrated in Gun Digest Book of Concealed Carry. You can usually find it at Barnes & Noble or the WalMart gun counter. Take a look at your convenience, and if it's not there, please get back to me.
Be sure to do plenty of initial practice with dummy gun or triple-checked-unloaded firearm before working with it loaded.