I've recently been motivated to share my sources of addresses because I'm often asked what sites/lists do I use to find addresses of athletes. The following sites or products have made a big difference in my ability to collect autographs. So I thought this may be of help to others. Beyond being some of my favorite links these are the tools I use each day to collect, I only promote the sources of information that I use.
Sports Collectors Net is the centrepiece of the hobby and hands down the best site for our hobby.