Microsoft Dynamics team have released 44 new Dynamics CRM 2015 videos on their YouTube channel covering the majority of new features, enhancements and updates in the Microsoft CRM 2015 release.
The list videos cover a variety of subjects including business processes, Mobile and Tablet apps new features, SLAs, Upgrade from CRM 2013 to CRM 2015 and a lot more. You can go and watch all videos in order from the following YouTube play list:
Alternatively here is a list of all videos with a single link to each video separately. Hopefully this will help: