WWW.SERZH.RU - Excellent informal web-site built by Sergei Fedorov. One of the best introduction into the history and culture of our city. A lot of nice photos, maps, stories. We are going to translate this site into English soon.
http://www.300.spb.ru - The official web-site of Saint Petersburg's 300th anniversary (1703-2003). The nice and informative site but is still under construction.