Here you can find everything to do with electricity and the science behind it. I will add to it in time...
Electromagnet - Make your own
LED booklight (or anything else you want it for) - A really useful science project to try.
Lemon battery powered clock
Light bulbs - make your own
Motor - make your own simple motor
Motor powered by sound
Play dough circuits - a step by step of how it's done!
Robots - Make your own simple robot!