Welcome to the community Troy and to this wonderful site that will teach you how to grow awesome healthy dreadlocks. The dreaducation section at the top of the site has great tips for you, so does my post: http://www.dreadlockssite.com/forum/topics/just-starting-out-what-to-expect
So you want to start by twist & rip, if you do that method, let your hair section naturally first. It takes a couple of weeks for this to happen. Just wash 2-3 times a week with a dread friendly shampoo and stop brushing or combing. The hair will section itself to where it wants the dreads to be. These are then the sections you would use. Any length of hair will section, so you can do that now. Knots like to form and stay in hair when it is 5-6 inches long, but will section shorter.
For nice healthy dreads, do your reading first and learn all you can. .....enjoy your future journey...peace