ClemensDesign, You sure can sell your self published books as well as tutorials, how-tos, and the like. I see a lot of people who sell e-book style tutorials for artists in all types of categories as well to keep the costs low. Normally the e-book style how to's are listed under:
Supplies --> Handmade ---> Tutorials
Two other sections you may also want to consider since your style of book may not be full tutorial based, are these other two sections:
Books and Zines ---> Book ---> Books with Content
or
Books and Zines ---> Book ---> Instructional
Best Wishes.
