Man, this brings back memories. When I first learned I used the playgo.to[0] tutorials and then followed up to play at the "No Name Go Server" which had a consistent 20 people on at any one time. (Now it's completely gone). Sadly, there has been a rapid consolidation in the space - that server along with Yahoo, MSN games have been deprecated. Even KGS [1], once the largest English go server, has been losing players and is dying a slow death. I moved to WINGS and Dragon later, but it was always so-so.
Probably my favourite place to play now is either on Pandanet [2] or the online go server [3] but it isn't quite the same, and (for me) there isn't the same sense of community that I had, even on MSN games.
[0] http://playgo.to/index-e.html