See the full schedule of the GNU 30th celebration on the main page.
The GNOME project will start with a Newcomers Workshop at 1:30pm EST on Saturday, September 28. We will help newcomers fix their first bug and will have a hackathon working on the GNOME 3.12 features later in the afternoon and on Sunday, September 29.
Bring your GNU/Linux, Windows, or Mac laptop - we will help you install a GNOME system in a virtual machine if you are not yet a GNOME user.
Join us in #gnome-love IRC channel on GIMPNet (irc.gnome.org) to participate remotely - here is more information about how to join IRC and its usage for collaboration on GNOME development.