This post has been edited, thanks to all of the awesome and uber cool magic kiddos here at Theory11. Your advice and professionalism regarding my many postings here on this site has been invaluable....
Byron Wells's Great Illusions of Magic is a great starter. Paul Osborne sells individual plans as well as books of plans. Sometimes you can find the old Thayer blueprints on ebay. I have a friend who has framed many of them.