As a teacher, you can create a group book where each student contributes certain pages in a collaborative book.
First you need to ensure that all of your students have StoryJumper accounts.
On your class page, click "People" and click "Add Students".
Then add students to your class using one of the options displayed.
Once all students have accounts, then there are 2 ways to set up group books:
1) You set up the group books
On your class page, click "Books", click "+ Create Book", and click "+ Group Book".
Once you're in the editor, you'll be prompted to add students to the group book.
Begin typing their real names and then click on their names.
You can enter each student's name on the pages they are assigned to, so they'll know which pages to focus on.
When those students login, they'll see the group book in their accounts.
2) Students set up their own group books
Assign one person to be the leader of each group.
They'll be responsible for creating the group book and inviting the other group members to the book.
To do so, the leader would click "+ Create Book", click "+ Collaborate", and type in the names of the other classmates.
Then all of the group members can work on the same book simultaneously.
They should plan what content each member is responsible for so they don't overwrite each other's work.