Posted By:
zachNot a price guide BUT this is needed if you want to get serious about collecting and learning, Encyclopedia of Baseball Cards by Lew Lipset. It has prices but they are from the 80s so they won't really help you. I would suggest the SCD aka the big book if you are looking for something for pricing a card or just looking at completed listings on ebay.
Here's a link to the Lipset book-
http://cgi.ebay.com/Encyclopedia-of-Baseball-Cards-by-Lew-Lipset_W0QQitemZ8744132206QQcategoryZ26362QQssPage NameZWDVWQQrdZ1QQcmdZViewItem