Open any word processor that supports images, such as Word, WordPerfect or OpenOffice Write. (Openoffice Write is free.) Go to the "File" menu, choose "Page Setup" and set the paper to landscape mode. This gives you more width, which is ideal for creating picture books. Format your pages with 1-inch margins on the top, bottom and right sides. Set the left margins at 1.5 inches. This will ensure there is ample room for binding.
Build your story around your photographs. A picture book relies on a combination of text and images to tell a story, but the pictures should be the focal point of the book. Go to the "Insert" menu, select the "Picture" option, then select the desired photograph on your computer. The photograph should show the main action taking place.
Write three to five lines of text below each photograph. Your text will be primarily dialogue between characters or more narrative about what's taking place in the photograph. Choose a font from the font menu that is cute but easily readable. If you don't have the appropriate font installed on your computer, you can find children's fonts online at no charge.
Change the formatting of a few pages for variety. One or two pages might include a full page of text and no photograph. You might have one or two pages that include only a photograph with no text.
Save your book as a PDF file. You can do this with your word processor, or you can download a free virtual PDF printer such as CutePDF and create a PDF using the print command. Once you've saved your children's picture book, you can take it to a professional printer or upload it to an online self-publisher that specializes in making children's books.
Print and bind your book with staples if you prefer not to have it bound professionally. This option is ideal if you don't want to spend a lot of money and just want to create a book for personal use. Stack your printed pages and place three staples along the left edge of the manuscript to bind it.