The Jenkins community congregates in the #jenkins channel on the Freenode IRC network.

Connect

In order to connect to the Freenode network, you can use a local client or the Freenode web client to connect. If you're using an IRC client, connect to the Freenode network (irc://irc.freenode.net) and /join #jenkins.

Backlog

The echelog bot in the #jenkins channel is responsible for logging the conversation for archival purposes, the archives can be viewed here

Etiquette

"Core" members of the community (such as kohsuke) will have "ops" in the channel and most developers will have "voice".

If you're looking for help, go ahead and ask your question, there's plenty of helpful people idling while their builds finish.