Hi Tara,
If you are a visual learner, I would be remiss if I did not direct you to Pinterest. We have an auction board on Pinterest that I think you will find helpful. You can also do general searches on PInterest with terms like "school auction" and you are bound to find many good ideas!
Every year our school holds an annual theater dinner where the children put on a play, a dinner is served and there is an art auction. Children in grades 3, 4, and 5 participate in the show. I am looking for some new art ideas that can be used. We have done furniture, mirrors, tiles, bowling pins, and such.
All the children in the school get to participate in the art project with the art program. Just looking for something new.