There are some main industry websites. Our site (
http://www.heritagesportscollectibles.com) is really good as far as a pricing tool for collectors. We deal with vintage items, but if you're looking for a rare card or something similar I would recommend a site
http://www.beckett.com/default.asp. They handle all the card pricing. Beckett has been doing pricing for the sports card industry since the early 1980s. They are the industry standard to determine what cards are selling for. Their website is really helpful for looking up prices and that type of thing. If you want to look up prices for vintage items our site is good. We have got a record of every item that we have ever sold in archive. The record includes what the item sold for, what the date of the auction was, and images and a description.
There is one more site that we host call autographs.com. The site is for
autograph collectors. Autographs.com hosts over 20,000 signatures that have already been authenticated that collectors can use. A collector would go to the site to determine, for example, if a Joe DiMaggio autograph that someone is offering is real. Our site has lots of examples of previously authenticated autographs that have sold so a collector can compare the stats to his deal, just to make sure that everything lines up.
Finally there is a site that I recommend for autograph collectors called psadna.com. PSA stands for Professional Sports Authenticators and they are the most widely known and recognized authenticators in the business. PSA started with cards, so they grade and authenticate baseball cards and now they authenticate autographs