i had a thought, and here it is:

1.a book of somekind that allows the user to record info (notes)
this "book" would have to be magical and when u either recite identify or cast identify it records all the data, (for example, if i cast identify onto a potion, the book would record what exactly the potion does) (this would kinda be like the glowing sword that you get at the begining, but it just sits in ur inv and doesnt go away

2.a book containing all the information on all the potions, magicial eq, and directions to major cities and some interesting places all within it. this would be worth a great deal, so it would have to be a prize for the ball game or the prize to some obscure, VERY challenging quest

that would be my ideal object within the game, one of the 2

Interesting ideas - Some issues include some objects that have variable attributes such as +1 int or no bonus, or 23 mana instead of 27 mana so the same piece of equ would identify differently.

As for a book of knowledge it could only have a certain amount as knowledge is gained by playing and exploring. It could be interesting if the book was harder to find than the information contained within.

I generally store my "knowledge" such as logs, my own maps, object locations and attributes in notepad / excel elsewhere on my computer - or just remember it.

Furthermore this forum is a good information source - if there are things missing that you would like to know just post and answers often fly in.