Evil Librarian:

Evil Librarian By: Michelle Knudsen
Fiction: YA, Paranormal, 343 pages
Book Count: 2

First, I would suggest that everyone check this book out of your local library, just to hear what the person checking you out says about them being or not being an evil librarian.
As far as the book itself goes it is very much a young adult novel and according to the quote on the back a beloved book of Stephenie Meyer, so there's that. . .  But the story itself is interesting enough to make up for the love-sick female lead and the impossibly perfect love interest.  Cynthia's best friend Annie falls in love with the new school librarian, who Cynthia can tell there is something wrong with.  After snooping around the school, she finds out that the new librarian is a demon who is sucking the life out of the student body.  She with the help of Ryan (her crush) then try to stop the demon before opening night of the school play that they are both part of.  (As they are doing "Sweeney Todd" which all demons love, so he isn't going to kill all of the people in the school until after seeing the play.)