It’s always good to have a little magic in your life, but this is fairly comprehensive. io9 have created a graphic explaining ‘The Rules of Magic‘ (more explanations than rules really) as found in some of the great fictional works of fantasy (click on the cropped image below, and say “Maximus graphicus!” loudly, to view the full-size chart):
Any others you think they should have included, or any obvious errors in the ones listed?