Here are some interesting vintage sports related links of people that I recommend.
Vintage Bobbleheads/Nodders
Sports Memorabilia Auction Houses
Vintage Reproduction Sports Pins
Huggins And Scott Auctions
Sportscard & Autograph Authenticators
Sportscard Guaranty
JSA James Spence Authentication
Sportscard & Memorabilia Forums
Game Used Universe Auctions/Forums
Net54Baseball.com Forums
Sportscard Companies
Topps Card Company