Railroad & Shortlines Club of Chicago
merger of Shortlines of Chicago Historical Society and The Railroad Club of Chicago

Central Electric Railfans' Association

Motor Bus Society

Calendar of Events for the Chicago metropolitan area

Shore Line Interurban Historical Society, publisher of First & Fastest

Bill Vandervoort's site, Chicago Transit & Railfan, has a historical perspective on the Chicago transit system, including a nice list of locations of former bus and streetcar barns! There are also railroad maps and past and present routings of intercity trains approaching Chicago.