Here is a good article on 8 different ways to structure an eBook from Geoff McDonald: book style, sequence, the 4MAT model, randomly, loose groupings, alphabetical, time, and beginner, intermediate, expert: http://geoffmcdonald.com/eight-classic-ways-structure-ebook/
An important part of an eBook is the visuals – you want to make sure to include lots of pictures, graphs, illustrations and/or images. Your cover needs to grab people’s attention. The images should be relevant to the text.
Other things to consider when writing your ebook: can you make your ebook interactive or dynamic? Can you include a social element? Can it be immersive?
Here are some steps you might want to take in writing your ebook from Darren Rowse at http://www.problogger.net/archives/2009/09/16/thirteen-steps-to-write-and-publish-a-free-ebook-in-thirteen-hours/ :
- Write an outline
- Do a first draft
- Add imaging
- Edit your draft and insert links
- Create an appendix of resources and table of contents
- Create the front cover and a graphic on it
- Do a final proofreading and link check
- Convert your ebook to a pdf
- Check text and links to make sure everything is as you want it to be
- Publish your ebook
- Start marketing