The simple living network is full of resources, including books by some of the founders of the voluntary simplicity movement and a free on-line newsletter that is published once every couple of months.
A definition of simple living can be found here. How does this definition align with or diverge from your own thoughts about simple living.
Choose simplicity explores the differences between voluntary simplicity and frugality.
And if you are interested in a model of a locally-run group, check out the San Diego Voluntary Simplicity Group.