I learned the kip completely by myself using the crossfit website. I watched videos of the WOD's and the videos that were posted to teach people the kip. I like to think i can do the kip pretty good now. Its all about finding the right rhythm to get the momentum for the next kip. I still mess up, especially when i'm tired, but i get better and better. Practice it once you've got it.
Iv'e learned that there is kind of two kips that i havent heard too many talk about. One is a fast fluid kip that allows you to rack up reps pretty quickly and efficiently. The other is slower and it is kind of like starting each kip from the start without letting go of the bar. Check out some videos and see if you can see what im trying to point out.