I self published a young adult ebook with Smashwords It's easy to upload books, Smashwords has a free "style guide" that says how to format books, and they distribute to B&N, Kobo, apple etc. I also published with KDP (Kindle Direct Publishing), they have slightly different requirements but are still easy to upload. Re. Illustrators, mine is a student friend who illustrates perfectly for my style of writing. It's like she can draw what's in my head. Look for pictures you like, and see who draws that way, and if you find your perfect illustrator, keep hold of them!