Okay let me see, got the following books out:
Fiend Folio,
Lords of Madness,
Book of Vile Darkness,
Monster Manual III
Yeah, I am ready to get working on the Isle.
And the "Book of Fey-mous centerfolds"!
Don't forget the book: "Things That Only Elves Can Touch"
Hey - don't forget these:
The Tome of Hobbit-sized Loot
The Pint-Sized Gear Guide
The Manual of Things that Only Harm Characters over [this] Tall
That should round out your bookshelf nicely.