In addition to the various MySQL mailing lists, you can find experienced community people on IRC (Internet Relay Chat). These are the best networks/channels currently known to us:
freenode (see http://www.freenode.net/ for servers)
#mysql Primarily MySQL questions but other database and SQL questions welcome.
#mysqlphp Questions about MySQL+PHP, a popular combination.
#mysqlperl Questions about MySQL+Perl, another popular combination.
EFnet (see http://www.efnet.org/ for servers)
#mysql MySQL questions.
If you are looking for IRC client software to connect to an IRC network, take a look at X-Chat (http://www.xchat.org/). X-Chat (GPL licensed) is available for Unix as well as for Windows platforms.