Book fair tips?

I have my first ever book fair this week...ah!  I have some seasoned volunteers who are able to help out but I'm still nervous!  

The previous librarian had used Scholastic in the past and had booked this fair already.  I'm not totally thrilled because the PTO-run Scholastic book fairs at one of my former schools always had a lot of junk - literal junk (toys), as well as a lot of junky books.  Also, a lot of the paperback books I got for the library fell apart after a few reads, which was very disappointing. I like the idea of using an independent book store instead of Scholastic but there really aren't any in my area (compared to Boston where I was before).  Anyway, the kiddos are very excited and all love books and reading so I think it will be fun overall.

I've recruited parent volunteers and had 4th graders make posters to hang up around school.  But otherwise, I'm feeling very unprepared!  Do you have any advice to make the book fair run smoothly?  Ideas for setting up?  I'll take any and all suggestions!