SQL Server 2012 Reporting Services Setup Considerations

Buy SQL Server Reporting Services and Related Software
Review Pricing and Licensing http://www.microsoft.com/sqlserver/en/us/get-sql-server/how-to-buy.aspx

Decide edition - Review supported features and decide whether it fits requirements
http://msdn.microsoft.com/en-us/library/cc645993.aspx#Reporting

Review further requirements (if part of a wider implementation)
Deployment Checklist: Reporting Services, Power View, and PowerPivot for SharePoint http://social.technet.microsoft.com/wiki/contents/articles/add.aspx
Leverage existing investment in SharePoint with SharePoint integrated mode - http://social.technet.microsoft.com/wiki/contents/articles/15178.sql-server-reporting-services-in-sharepoint-integrated-mode.aspx

Decide Reporting Services mode
Native mode needed for all of these programs that use SSRS -
Forefront - http://technet.microsoft.com/en-us/library/bb404235.aspx
CRM - http://msdn.microsoft.com/en-us/library/cc308177.aspx
Operations Manager - http://technet.microsoft.com/en-us/library/hh298611.aspx
Team Foundation Server - http://msdn.microsoft.com/en-us/library/dd578652.aspx and http://msdn.microsoft.com/en-us/library/jj620927.aspx

Handle different setup scenarios
Install Reporting Services Native Mode Report Server (SSRS) http://technet.microsoft.com/en-us/library/ms143711.aspx
Upgrade and Migrate Reporting Services http://msdn.microsoft.com/en-us/library/ms143747.aspx
Install Reporting Services and Internet Information Services Side-by-Side http://msdn.microsoft.com/en-us/library/bb630449.aspx

Decide on scale-out deployment
http://social.technet.microsoft.com/wiki/contents/articles/15179.sql-server-reporting-services-scale-out-in-native-mode.aspx

Related documentation
Installing Reporting Services http://msdn.microsoft.com/en-us/library/ms143736.aspx

Troubleshoot Problems
Troubleshoot a Reporting Services Installation http://technet.microsoft.com/en-us/library/ms144289.aspx
Troubleshoot a Reporting Services Upgrade http://msdn.microsoft.com/en-us/library/hh759330.aspx