There is an ever-expanding amount of information on the Internet available for Community Managers.
There are several excellent books available on the subject and one that we recommend is The Art of Community: Building the New Age of Participation (Theory in Practice)
by Jono Bacon.
Depending on how serious you are about being a Community Manager, you may want to investigate The Community Roundtable, a professional association designed just for that purpose. run by Rachel Happe and Jim Storer, they have an amazing grasp on what it takes to be successful and have built a Community Of Practice that has people from all sorts of organizations involved. They have a great newsletter as well.
Enjoy your role as the Community Manager, you are in fact the Life of the Party!