I developed this classroom library check-out sheet to solve the problem of missing books from my personal library. It's a simple excel document that allows for editing to suit your needs.
I like to three-hole punch these sheets and keep them in a binder near my desk and print additional copies as needed. Students can either be directed to fill out the sheets themselves when they "check out" and return your books, or -- if you're a bit obsessive about your library books like I am -- you can develop a system where students bring books to you during designated times for you to fill out the sheet yourself.
This has become a great resource to me, especially as I notice books that have been checked out for a long period of time so I can talk to that student and ensure I eventually get my book back! Ever since I started using this, my students have been well aware that I am keeping careful track of my books, and far fewer have gone totally missing using this simple tracking device.