I would advise to sell on limited registration...especially as you first start out. IMO, you shouldn't sell a dog w/ full rights unless it is going to be to a show home or a breeder who is going to work to improve the line, not take it a step backwards, not to a pet owner. That type situation would require a certain level of involvement on your part, which is alot to take on when you are just starting out and still learning yourself.
Also, as others have mentioned, you may want to consider having the pups s/n before they leave your home...that way you eliminate all possibilities of alternate registration or accidents in the future.