Dont breed your dog back to its mom.. father daughter or uncle neice or nephew aunt or cousin/aunt to cousin/nephew LOL inline vs line bred ... inline is direct such as father daughter or brother sister.. line is the cousin or nephew aunt or uncle neice but some line bred dogs are complex and are cousins, aunts, and half siblings all at the same time.. LOL
study some peds of the greats before you jump off linebreed your dogs.. Google the Punit Square and understand it and the dominant traits you got and what your doin with your dogs before you breed them as well; it will be better for your own understanding and give you insight to the form of line breeding that will work best for you and your dogs. Try to contact a few established open yards and see if you can visit and inquire them while your there about line breeding and just learn all you can before you let the dogs get locked up..