The New Rights Management Service - a blog series that explains it.

A great blog series that explain it. It consists of multiple parts:

• What is Rights Management
• Turning on Azure Active Directory Rights Management
• Managing Azure Active Directory Rights Management
• Enabling AADRM in Exchange Online
• Enabling AADRM in SharePoint Online
• Configuring Exchange On-Premises to Use AADRM
• Configuring SharePoint On-Premises to Use AADRM
• Using AADRM from Microsoft Office
• Using AADRM to protect anything else

It starts here:
http://www.c7solutions.com/2013/11/the-new-rights-management-service