Baseball cards? Are they worth anything?

Get a Beckett Magazine and look them up. They make a Beckett for each sport. You'll need the year, brand, and card #. It depends if you have any inserts or special cards. If you want an answer to how much they are worth here, you'll need to provide more specific information. Each of the players you named has thousands of cards. As for the 1982 Fleer pack, I wouldn't expect more than a few dollars.