Check out Simon Lovel's Packet Killer DVD set. Make sure to order the DVD with the gaff cards to go along with it.
If you are looking for uses of standard gaff cards like double back and double face, check out the book Encyclopedia of Card Tricks.
To avoid knuckle-busting techniques, check out Scarne on Card Tricks, Encyclopedia of Card Tricks, Card College Light/Lighter/Lightest and Steve Beam's Semi-Automatic Card Tricks.