Have used Student Treasures...
for two years now and love the company! The students each receive their original writing in a hardbound published piece. Parents and other relatives are able to purchase reprints of the child's book. It is time consuming during the process and in preparing the final kits for shipping to arrive for the press date. You might want to consider asking volunteers to help with conferences, assembly, and packaging.
I am the coordinator in our building, but I really feel the students enjoy becoming a published author and learn what it takes to create a book. It also reinforces your writing process and traits from other classroom writing tasks.
Good luck on your publishing adventure!!