When entering a regular book in my database, for which there is no other entry, how do I ensure that is shows up on Atomic Avenue?

Can you clarify your question?  Are you talking about a book that isn't in the master database?  

This sounds like a question for ComicBase. On Atomic Avenue, we have different sections for comic books, magazines, and books, so make sure you are looking in the right section. If the book is not in ComicBase, it is not on Atomic Avenue. You can add it as a correction, and when the editors at ComicBase review to make sure it isn't redundant with an items that is already in ComicBase, they will add it to ComicBase. It will propagate into ComicBase and thus to Atomic Avenue on the next update, and you can then put in however many copies you have into your ComicBase database and it will appear on Atomic Avenue for sale.