Just beat the game and save the info to your memory card then go to bonus materials to see them. Don't worry about finding the tomes, they are all opened when you beat the game:

Kain's tomes - found throughout Kain's journey
Making of LOK Defiance - finish game and save to memory card
Raziel's tomes - found throughout Raziel's journey
Soul Reaver 1 - opening start new game
Soul Reaver 2 - opening start new game