This week's site is a must see: SNAMA.
They say it best themselves:
"With over 1,000 individual members, SNAMA represents one of the largest dedicated communities focused on sharing best practices and information on social media and community management. Whether you are from a traditional association, are interested in creating a community of interest or want to create an engagement strategy for your customers, SNAMA is the forum for discussion and learning.
SNAMA provides you with:
Job posting / search
Membership is free and everyone with an interest in social media is welcome!"