SCHEMA Microdata tools

This markup tool for Schema tags allow you to pass it an url of an existing page, then highlight data on the page and identify what it is. When you are done You can view your existing html with the schema content added and highlighted for you.

https://www.google.com/webmasters/markup-helper/

And once you enact the markup, this tool will help you verify it
http://www.google.com/webmasters/tools/richsnippets
http://linter.structured-data.org/

Or try the "schema explorer" plugin for Chrome. https://chrome.google.com/webstore/detail/docnladpefffgdocnidfngejcagdkedb