ahhh the 6th book in the increasingly missnamed Hitchhiker's Guide to the Galaxy trilogy!
(I really liked those)
There is a "set" of Star Wars books, (not really a set but...) They are "The Essential Guide to _______________"
where the blank is like Planets, Weapons, Ships, Characters, ect.
I am currently on the one, "Jedi VS Sith The Essential Guide to the Force.