Liz - My students have worked with Scratch, Alice and Game Maker and they would rank them in that order of difficulty.  I think you could use any one of them, and everyone else's comments on knowing the programming are valid.  

What I liked most about what I've done the last 2 weeks is the holistic approach.  I've been to the Alice Institute, I've been to the Microsoft Game Days Cruise.  This approach is not focused totally on the programming piece.  

Anyway, if I can help you out, I will...I got about 3 weeks laid out.  What do you think is the best way to share this info?  Google Doc? or something else?