Mobilegeddon is Here

What Is Mobilegeddon & The Google Mobile Friendly Update

http://searchengineland.com/library/google/google-mobile-friendly-update

Link to Test mobile-friendliness of your website: 

https://www.google.com/webmasters/tools/mobile-friendly/

How to make website mobile-friendly:

http://searchengineland.com/tomorrow-is-mobilegeddon-are-you-ready-for-the-google-mobile-friendly-update-219291

Other useful links on Mobilegeddon:

http://googlewebmastercentral.blogspot.in/2015/02/finding-more-mobile-friendly-search.html

https://www.seroundtable.com/google-mobile-friendly-label-test-20044.html