Do not hesitate to ask questions, and do not panic if somebody doesn't answer your question immediately. A few of our devs maintain a persistent connection to IRC even when away from the computer, and will most likely try to answer your question if you're still online, even if it may be later during the day.
If you need to speak to someone in particular, you may try mentioning the nickname (ex.: "nekohayo") if that person is online. See also the main list of people involved in the project.
To discuss features, implementation details, or simply get some help, subscribe to the mailing list. This is roughly the equivalent of a forum that uses your email account. There is not a lot of traffic on the mailing list, so you will not be overwhelmed by mail (at least until we reach world domination status).