Knowledge is power
This book may be intended for kids, but Electronics for Kids is a great way to demystify electricity and circuits for anyone who learns best through doing. The concepts are accompanied by hands-on projects (23 of them), that'll make your 12 year old ponder an electrical engineering degree and you more confident when you rewire that ceiling light.
If you want to get started with supplies before the book arrives, here's www.nostarch.com/download/ElectronicsforKids_updatedpar...
" target="_new">the parts list for the stuff that you'll need to do all the projects in the book.