For trade cards in general, The Trade Card Place has a lot of good info.
http://tradecards.com/
For baseball trade cards in particular, this site is the place to go:
http://www.schenectadyhistory.org/ba...rds/index.html
I have over 10,000 different trade cards, including around 200 different baseball-themed ones, and I’m happy to point you toward any specific information you need.