Note: before you can join, you need to register your nickname - see http://freenode.net/faq.shtml#nicksetup for detailed info.
Edit by JensRex:
If you join #foobar2000, don't do this:
CODE
[15:09] * user (n=user@example.com) has joined #foobar2000
[15:10] <user> help
[15:11] * user (n=user@example.com) has left #foobar2000
[15:10] <user> help
[15:11] * user (n=user@example.com) has left #foobar2000
Don't say "can anyone help" and wait for someone to react. Just join and ask your question. People will respond if they know the answer.
Also note that most of the #foobar2000 regulars live in Europe, and while some of us tend to stay up much longer than we should, chances for an immediate response are lower during night time in Europe.
Comments on third-party support moved to a separate comment by Canar.