Hi,
Of course, my own favourite would be my own site
http://www.spankingsarah.com It has been running for just under a year but thankfully, seems to be very popular.
I also like
http://www.english-spankers.com but as this is run by my wonderful partner, I may be a little on the biased side.
Both sites are most definately worth a look.
For spanking chat, I am very active on a new social network site
http://www.worldfetishforum.com In fact, I am one of the moderators over there.