Here is the release overview presentation with screenshots highlighting the important features and functionalities introduced in Salesforce Summer 16 Release

For videos, release notes and other resources on Summer 16, please navigate to URL http://www.salesforce.com/customer-resources/releases/summer16/

And here is the link to some great blogs summarizing the useful features in Summer 16 release

And here is the list of past release overview decks

  1. Salesforce Spring 16 Release Overview with Screenshots
  2. Salesforce Winter 16 Release Overview with Screenshots
  3. Salesforce Summer 15 Release Overview with Screenshots
  4. Salesforce Spring 15 Release Overview with Screenshots