Here are some great resources I have found for social marketing metrics.
1. Social Media Metrics slide-show by Laura from Dooley from the World Resource Institute is fantastic. – lots of free ways to track your conversations.
3. Buzz numbers is another good tool.
4. Omiture have a great video that teaches you how to test and optimise your web in terms of layout, functionality and testing these constantly to optimise your performance with your key metrics.
5. Are you being talked about? Go to Social mention. Great feedback on how you are entering conversations and what the audience feels about your content.
6.If you want to look at a metric that measures your worth as a social media influencer go to twitalyzer.
7. Woopra is an alternative to google analytics.
8. Best article on social metrics I have found, heaps of information.