Q. How can I calculate my H-index? What is the best explanation of the Hirsch Index?

You can calculate your H-index by setting up profile in the Google Scholar Citations.

Web of Science also provides an author H-index. 

1. Search for the author's name (for common names add another search box and search for the university zip code in the address)
2. Click on Create Citation Report, on the right side of the results
3. The h-index is located in the summary area next to the citation charts

The Hirsch Index is 'a scholar with an index of h has published h papers each of which has been cited in other papers at least h times'

Another widget for Google Scholar is Harzig's Publish or Perish