Playing my first wizard here next week. I was wondering if there was any cool, flavorful, but legal ways of pimping out your spellbook? What are some of the customization you tried?
Pimpimg it out how?
Is this PFS or home game?
PFS not too too much you can do, you can put a lock on it, line a few pages of spells you don't use with some poison, or cast a variety of spells upon it such as Arcane Lock, Sepia Snake Sigil, Book Ward, Phantom Trap just to name a few.
Home Game you have all of the options in PFS plus in the 3.5 Complete Arcane they had a table for making books of differing materials, bone, stronger papers, and even metal, my dwarf wizards favorite. It may weight a ton, but you can pretty much use it as a shield and not worry much about it.
Try "ye olde" 3.5 Forgotten Realms manual "Magic of Faerun", it has a whole section on how to make spellbooks fire- and waterproof, resistant against small vermins, and so on.
EDIT: The "whole section" is rather small, but interesting.
Ask your DM what he allows in game. I have 2 Wizards in different games, one has to have 'spares' while the other has a necklace with gems enchanted as a spellbook (think Rosary, higher cost, but worth a lot less). The other Wizard in the second game keeps a loose 'folio' pouch as a spell book, each multi-page spell being bound together, with his viper familiar living in there.
Ultimate Magic has a section on custom spellbooks that you could use for inspiration. Spells like Bestow Curse could be tailored to curse anyone who touches your book but you and the party.