You can search Ebay or sports memorabilia sites for a quick reference on specific cards, to sort the junk from cards that may have some value. Be aware that if the cards are not in absolute mint condition, they will generally be of little or no value, except in some cases where the card is very rare. As is true with all collectables, sports cards will only have a true value of what a collector is willing to pay for them; not what the seller is asking.
Good luck.
I'm sure I used my Mickey Mantle rookie cards in the spokes on my bike.