I just came across two great sites from the federal government (yes I realize some will see that as an anomaly):
HowTo.gov and it's heir apparent, ​DigitalGov.gov.
Both sites have a lot of great resources, tips and best practices for web and rich media design – including UX, Metrics and Social Media.
There's even a recent post with a template infographic for measuring social media metrics. I know a few community managers who will appreciate that.
