Subscribe to the current Turn thread and the threads for the other four teams.
You don't need to subscribe to the History thread if you stay abreast of the current turns. I started that thread so that new team members would have a way to know what has happened in the game without digging through every thread in our forum.
Once you are up on current events, just pay attention and respond to events as they happen. If you have an idea or question, post it in the proper thread(s).
This is like a slow moving SG, played one turn at a time, where everyone has input.