If you have $20 lying around, and are a fan of Mother/Earthbound, you should definitely pick up the Mother 3 Handbook. If you're a fan of the game and don't have $20...well, lucky you.
Because you can browse and download the book for free. While the luxurious book costs $20, and a hi-res .pdf file of the thing costs $6, there's a low-res version up on Fangamer's website that can be read and, if you're short on can-reading material, downloaded then printed off.
Isn't as nice as the real thing, but then, some of you are cheap bastards.