2013
RMS Setup Guide
http://sp-vinod.blogspot.com/2013/08/configuring-information-rights.html
http://sp-vinod.blogspot.com/2013_08_01_archive.html
Good Article
https://social.technet.microsoft.com/Forums/en-US/df9796b5-6a1a-43c7-ac32-c77d2ec68e1c/ad-rms-2012-irm-permissions-for-sharepoint-2013-library?forum=rms
Good Video
http://channel9.msdn.com/Events/SharePoint-Conference/2012/SPC073
More Good Links
http://technet.microsoft.com/en-us/library/jj219596%28v=office.15%29.aspx
http://technet.microsoft.com/en-us/library/jj219785%28v=office.15%29.aspx
http://www.titus.com/blog/2012/11/spc12-diary-day-5-%E2%80%93-information-rights-management-in-sharepoint-2013/
2010
RMS is a complex process, first the AD team has to setup AD RMS then you turn in on in SharePoint. This is similar to the email configuration.
https://technet.microsoft.com/en-us/library/cc179103.aspx
The first part is AD RMS that your AD team needs to setup but since this depends on the server OS. Here is the 2008 setup guide https://technet.microsoft.com/en-us/library/cc753531(v=ws.10).aspx
then SharePoint RMS https://technet.microsoft.com/en-us/library/hh545607(v=office.14).aspx