I just received a book today and I was adding it to my to be read list, and PBS tells me when I put in the ISBN# that it's a valid number but isn't in the data base. How do I get it there?

What is the ISBN for the book, and its title and author?

I know how to add a book thru posting and if there isn't anyone wishing for the book you can add it that way and then put it on hold so that no one can request it:

From the post a book tab enter the ISBN, and it will bring up a data page where you can enter all the pertinent information. This will put the book in the system as well as post it, so be sure to put it on hold so it can't be requested. I've had to do this frequently lately, mostly for book club editions.

if it is a book you received thru the system, the sending member did not post it properly, so the ISBN didn't match and you could have RWAPed it as wrong book sent as ISBN numbers must match.

Doesn't PBS automatically add books when you search them?  I seem to remember someone saying that in this forum a while back, most particularly if you're searching for a book to put on your wish list.  PBS links to another database and adds the books if they're not in the system.  

Check back in a few days and see if it comes up.

Searching for a book by ISBN, will cause the system to hunt for the listing via the database (iirc).  It doesn't hurt to search maybe 2-3 times within a day. Sometimes you'll find the listing is added within a few hours and usually a couple of days. If it doesn't find and open the listing within a few days, and you know it's a valid publication/ISBN, contact the PBS Team.  

If you have a book you want to post but there is no listing for the ISBN, DO try posting a single book by ISBN - if the system recognises it as a valid ISBN, it will set up the opening form WITH the ISBN.  You still have to add all the data, but it opens as a regular listing, not a short- or non-ISBN.