If you still have time and energy...
Start your Classroom Library
Having a classroom library will make a world of difference to your choice reading program, and therefore your students' love of reading, vocabulary development, and writing ability.
Summer is a great time to put the word out to family and friends that you are building a library, in case they have books to donate or can flag you for local book sales. It's also a great time to watch out for a cheap couch, armchair, or beanbag or two in your orbit.