Where can I find if these old books are worth anything?

You won't be able to tell much of anything about their worth without a professional looking at them in person. There are just too many variables with market saturation, print quantity, demand, mold issues, binding condition, possible missing parts (like dust jackets), etc.

Take them to a local antique book dealer or possibly a library school at whatever your nearest sizable university is.

Contact Better World Books. It's a great group -- their profits go to fight childhood illiteracy -- and they will list and sell your books for you.. probably know if they're worth anything, too.

Book value is the same as house or car value. Look around for a book appraisal person and have them look at your books. They can tell you the worth of the books :)

Ever heard of a rare or used book store or website?

antique road show