crazieflyer:

If you can find one, get an "Electri-Cub" kit. That will be a gentle intro to electrics for your grandson. Its flying characteristics might bore you, though. Avoid the RTF foamies. They wont teach you anything.

http://www.astroflight.com/

This is the site for my favorite ESC's, the astro 215D, and also Bob Boucher's excellent book "Electric Motor Handbook."

These two items should get you going.

Bill.