After a few minutes of checking it's decided the place is trap free... The book cases have books on them, but they are so old that you can't make out any form of writing on their bindings, There are, however, a few sealed scroll cases in the book cases as well.
The skeleton in the small alcove just seems to be sitting in repose, the books is covered by it's arms and seems to be held tightly.
Helata's detect magic notes that there are 6 sources of magic within the room aside from varying members of the party... the 3 cases, the book, the skeleton itself, and a single stone in the wall off to the left side.