I have worked on a year book. At our school we let the kids do the cover. And a 2nd place page inside. Have a contest... It is great the winner gets a free book.
Also have as many pages of the kds doing things. Ask what they would like to see in it.
Also make sure you have help!
I have been putting together the yearbook for years now. Couple of ideas:
Surveys - they love them. Poll the students, ask them a question, write their name and response.
Ask each class a question and do a montage page of the responses next to their portrait page. What do you want to be when you grow up? If you had one wish to come true what would it be? If you were principal what would rule would you change? Get the idea?
Teacher Time Warp photos. Fun, fun. Get old photos of the 6th grade teachers, place them on a page and put their names on the last page of the yearbook.
In my opinion the more montage photo pages you have the better. They love to see themselves in the book.