I've inherited a bunch of astrology books, and it's not worth my time to sell them on Amazon, so I thought I would list them here.

I don't see a subject "astrology".  I looked in "NonFiction" and "Reference" and don't see any sub-category that would not be misleading.  I posted one book under "Reference - general" but that would not be appropriate, really, for this book.

It seems like there should be a section on astrology, and also a section on psychic research and studies.

Try this: Religion & Spirituality >> New Age >> Astrology >>

I'm a little bit confused about why you need this info to post. Do the books not have ISBN#s?

Thank you.

These books are pretty old, some do not have ISBNs, and this is one of them.

It's hard to figure out the genre system sometimes.  When I'm posting a non-ISBN book, or submitting an edit, and can't find the genre(s) I want, I do a keyword search for similar books and check several of them to see what genres they use. 

That's a good idea.  I never thought of that, Patty.  And this is why I frequent this forum.

The genre system is not particularly well-organized and has many gaps, so it is not unusual to be unable to find suitable genres when posting books. I have contacted the Team about this and have been told that although the genre system used here is lacking in some respects, it is free and you get what you pay for. I agree that it is frustrating when unable to find suitable genres, so Patty's suggestion is good to try if you are having difficulty. Even so, some books simply won't classify well with the current genre system, so you just do the best you can. It also helps to include book descriptions when posting books or submitting data edits because these can clarify genre and subject matter.