I'm a beginner, too. I had the best luck with Kathy Smith and Gin Miller's Step Reebok. They both include very basic choreography that allows you to repeat the steps until your body learns the moves. After you get that down (several weeks, at least), you can do anything, although probably not the first, or the second, or sometimes even the third or fourth time you attempt them, if you're like me. I've finally worked my way up to Cathe now (Step Heat and Step Jam seem the simplest choreography-wise), but I have to admit to the minutes at a time that I stand simply staring at the screen on some of her other videos. But eventually I'll come across a part I can follow, and it seems like the next time I try it, I'll work harder on the parts I missed and get a few more of them each time. Right now, the only thing I'm still having a lot of trouble with is crossing over the step.
Good luck! It's worth the trouble. Stepping is really a LOT of fun!