This is easily the best basic introduction I've seen. Clear, well-illustrated, neither assuming prior experience nor treating the reader as a dummy, it can take you from Zero to rewiring branch circuits with confidence and safety.
I really can't recommend it highly enough! I already had experience, but picked up useful bits from it, and have loaned a copy to several friends.
The T/L Home Repair and Improvement series is good in general (more than I can say for most series), but especially this volume.