There are several types of skill-books [each type for every skill], which are "eatable" and dispappear aftre use:
Big Book of Science [Science]
Chinese Army: Special Ops Training Manual [Sneak]
D.C. Journal of Internal Medicine [Medicine]
Dean's Electronics [Repair]
Duck and Cover! [Explosives]
Grognak the Barbarian [Melee]
Guns and Bullets [Small Guns]
Lying, Congressional Style [Speech]
Nikola Tesla and You [Energy Weapons]
Pugilism Illustrated [Unarmed]
Tales of a Junktown Jerky Vendor [Barter]
Tumblers Today [Lockpicking]
U.S. Army: 30 Handy Flamethrower Recipes [Big Guns]
They give +1 point to skill [+2 if PC has "Comprehension" perk].
They're to be found in many places, sometimes in places like abandoned shacks/shops which aren't marked on main map, so some exploration is really needed.
Other books are some kind of joke - just another useless junk. I can understand that destroyed or burned books are unreadable and peeople keep them for sentiment or just forgot to thrown them away, but pre-war books which seems to be intact? It would be nice to find some fragments of classical literature or just anything to read there... That's a shame there's nothing there.