Attention: Knitters

How difficult is Fair Isle Knitting, really? I just ordered this booklet for the kids' crayon-and-alphabet vest, and the only knitting with different colors I have done has been Mikey's Jayne hat (which still needs ear flaps). I'm confident that I can do this, eventually. It's just a matter of figuring out what the heck I'm doing.

I need to dig out my Idiot's Guide again.