This corner of my art room at the middle school is where my students keep their art journals. 5th graders use their sketchbooks for brainstorming, sketching for projects and when they have extra time. 6th graders are doing an art journal on American Indians and the book they are reading for LA, My Side of the Mountain. This book has a great story that you can do a lot of comparison/contrast with how American Indians lived off the land and how the character Sam survives in the wild.
The bulletin board has a list of ideas for their sketchbooks and some pics from art journals that were online.