Okay, I found a bunch of books not listed here and I'm not sure if I can remember where all of them were but...

Dragon Skill Books:

* In High Hall Mines there's book near the chest next to a lava-pit. It's in the 'center' chamber of the cave.

* In Old Cave there's a book on one of the tables on the platform where you fight Barnabus.

* Two books can be found in Orobas' Lair. One's in the talking chest, the other is near the north wall.

* In Red Hammer Tribe's cave there's a book near Groth.

* A Book can be found in Dark Cave on a table near Ragon.

* Two books can be found in Primordial Cave. One is on the table in the Chicken Room. The other one is on the east wall of the Fire Maze.

* In Lost Tomb there's one to the right of the coffer.

Skill Books:

* In Old Cave there's a book in the chest near the Book of the Dead. The key for the chest is in one of the broken coffers in the previous room.

* In High Hall Mines there's a book on the table in the room where Mundus is.

* In Red Hammer Tribe's cave there's a book on the bench behind the only door.

Stat Book:

* One can be found in Champion Harbor near Aurelius.