Here are a couple links that dive in to the super metrics and finer points of the dashboards. They give EXAMPLES of ways to use them in different scenarios.
Iwan Rahabok posted two good docs on deep diving in to the super metrics and explaining how to use them:
http://communities.vmware.com/docs/DOC-18592
http://communities.vmware.com/docs/DOC-19415
Gregg Parsons did a super metrics white paper, it was written for 1.0 but still generally valid for 5.* versions
http://vmwmanagement.files.wordpress.com/2012/01/vcops_super_metrics_in_vsphere_environment_v1_0.pdf
While these may not cover every single widget, I'm sure these will help you!
Mark
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