Blurb - Create and self-publish books, magazines & ebooks
Open Peeps - A hand-drawn illustration library.
CreateSpace - Publish your words, your way
Control Illustrations - 108 free flat illustrations with customizable characters
IngramSpark - IngramSpark is an Online publishing services provider platform that allows you to publish or print books that are in high quality, and its global distribution service enables you to post and share around the globe.
DrawKit - MIT licensed SVG illustrations, in 2 styles