Writing a multimedia ebook or magazine can be a good way for students to illustrate and or further explain portions of fiction and non-fiction stories that they develop. Multimedia publishing tools that include a collaboration component can further help students as they work together with each other or with you to improve their work.
Book Creator is my favorite. If you are on a Mac, be sure to check out iBooks Author and Apple Pages. iBook is specifically designed to create ebooks. Although designed for word processing, Apple Pages has several page layout and graphics tools, along with export for epub that makes it a worth contender for creating ebooks. Both Apple products create epub files that are readable on all platforms.