Try and respond as fast as you can to make sure that people don't think the project is dead. - If people can get help with the project sooner, that means they will think better of the community.
Listen to everyone's opinion. - If you think something doesn't mean that you are 100% correct.
Make sure to read the contributing guidelines. (If they exist) - This will mean that you don't have to re-do abunch of contributed code.
... and all the discussion rules.