For additional stuff WRT spellbooks,
Magic of Faerun has an IMO
great section on spellbooks OTHER than the standard, soft-leather-bound parchment-page variety.
So you TOO can have a (say) Black-dragonskin bound spellbooks whose pages are hammered-ultra-thin plates of silver, contained in a silver-and-onyx ornamented, black-dragonhide slipcase, the whole benefitting from a Protection from Elements enchantment good for all five enchantments, and waterproofed to boot.
Just as one example.

On top of it all, the more you spend, the harder the book is to damage.
One spellbook I put together with those rules was made of Living Metal (chose the Hard Metal cover and pages, with slipcase, then paid the per-pound rate for "other items" in the Living MEtal entry (also in
Magic of Faerun), with all the defensive and utility enchantments / enhancements a wizard could desire. Each one cost just over 25,000gp ... but was nearly impossible to damage w/o having long before obliterated the fellow carrying it, AND, was self-repairing (the self-regenerative feature of Living Metal), so if even 1hp remained ... give it a couple days, it'll be good as new.
The variations possible are great; you can use cheaper, magically-concealed books for your "home copies", and strong, tough, protected-from-most-forms-of-damage books for travel copies, if you want. A book warded against wet and rot, and concealed right, coudl even be hidden in an exterior wall around a cow psture somewhere, to give your wizard an
emergency backup copy.
If, of course, your wizard has the kind of money it would take to
do that sort of thing ... heh.