Decide on the type of book you wish to write. You may decide, for example, that you want to write a work of fiction or nonfiction, a children's book or a how-to guide on a subject you are knowledgeable about.
Research your subject thoroughly. If you are writing, for example, a biography of a historical figure, look at both primary and secondary sources. If you are writing a work of fiction, it is often advantageous to review other works in that genre to get a sense of appropriate style and tone, as well as how successful works are structured. It is also advantageous to follow the basic "rules" of that specific type of work. For example, a children's picture book is typically no more than 50 pages.
Decide whether you want to publish your e-book in color or black and white. For example, Barnes and Noble offers the "Nook" digital reader in color, while Amazon offers the "Kindle" in black and white.
Choose a word processing program to write your work. You can use Microsoft Word or Open Office or another comparable program. Then, write your text.
Hire an illustrator if you want to include artwork or diagrams in your book. If you are an artist, you can create your own artwork or illustrations in a variety of programs from GIMP to Illustrator or do your work by hand and scan in images to your computer.
Bring your images into the word processing program. Position each image where you want them within your manuscript.
Using the word processing program you are writing your book, you can export your document in a PDF format. This format can be opened while using Kindle, Nook and iPad.