"Pinging Your Blog", what does that mean?
Pinging is a notifier or more like an informer that allows you to tell other indexing websites that your blog has been updated. Hence those websites, will have a chance to index your blog and increase its popularity.
So what do I mean by "increase its popularity". It is like when you search on google, you will see your blog on one of the search results and when users click on that result, they will be directed to your blog, that means more traffic! Remember, more traffic = more popularity.
Here are some websites that offer free pinging services:
http://pingoat.com/
http://pingomatic.com/
http://pingates.com/
http://www.pingmyblog.com/