There are several options, but we use the school-wide program. Primary teachers create class books with their students. In this project, each student contributes a single page to the class book. One free copy is bound for the class. Intermediate teachers create individual books. In this project, each student writes an entire book. The book is bound for free. Extra copies can be ordered for both types of books for around $20, but teachers can purchase copies for much less. I've purchased several over the years to use as examples for future classes. Student Treasures can be used for any grade level, not just elementary.
I've found this unit to be an authentic way to teach the writing process. While our class publishes one project each month, the unit that results in a hardback "real" book is always the best. I typically start the unit in early December and wrap it up at the end of January. In the sometimes chaotic Christmas season, Student Treasures keeps students motivated. It's also proved to be a great way to teach time management because we're on a deadline to mail the books out for publishing.
The last few years I've used alphabet books for this project. I use several mentor texts to show that alphabet books come in many varieties and aren't just easy books for developing readers. We also create anchor charts and idea lists to generate quality writing. Then the students select their theme and are off and writing. Some of our past topics included movies, sports, holidays, and school. When the bound books return in the spring, we hold an Author Party to celebrate and share. I love it!
If you're interested in Student Treasures, click on over to their website. If you decide to try it with your class (or school!), I'd love to refer you and earn Scholastic dollars for our school library. Drop me an email and we'll trade information. Thanks, and happy writing!