POST: Library Discipline

Hello! I am currently a library assistant at a very small
Title I school. We are part of the specials schedule and
have classes every Wednesday. So far the librarian will
read the kids a story and get them started taking an AR
test on it...while some kids are taking the AR test the
rest are just sitting on the rug waiting. Obviously as
they are all sitting there with nothing to do, their
behavior is awful. I have started sending those that are
waiting four at a time to get their books, so I can use
that as a behavior incentive since I pick the ones who are
best behaved to get their books first. However, after they
get their books and come back to the carpet the horridness
starts all over. Does anyone have any tips for behavior
management in the library? I am getting no back up from my
librarian at all. Also, the shelves are totally torn up
after the classes are over even though we have been over
shelf markers and how to put books up correctly. I try to
circulate, but with 15 kids on the rug and four roaming its
hard to keep up with all of them by myself. Any tips on
how to keep the shelves even a little straight while
classes are checking out? Thanks so much!