What is an easy digital program for an idiot?

Me and my sister are going to do a live action/animated short series and we need an easy animation program to do for half of it. can someone help?
it needs to look some what like the animation at 3:00-3:09 http://www.youtube.com/watch?v=GRPZd0enGCg

if you have a mac book the video maker app is simple and offers a variety of ways to edit your videos