useless and worthless. I had a collector's set from 1980's and I was told by a reputable business that there are just too many of them, unless they are signed by someone famous or something... Everybody and their mother collects them now.
Yes they are made of card and have pictures of ba<x>seball pla<x>yers on them, I hope this helped :)
If they are in good condition, take them to a collector. If they are all bent up, burn them.