If you have correctly integrated Reporting Services with SharePoint through the Central Admin, the mentioned below features are automatically activated as a site collection features in existing site collections in the farm.
Report Server Integration Feature
Reporting
After the activation, you can validate this when you go to Site Settings > Reporting Services
Manage Shared Schedules
Reporting Services Site Settings
So far, this only validates that Reporting Services are ready to be used in your SharePoint environment. In order to use reports, you need to create a Report Library and you need to add these additional content types to the library through library settings :-
Report Builder Model
Report Builder Report
Report Data Source
All of the above steps are correctly explained here:- http://www.codeproject.com/Articles/88285/Integrating-Sharepoint-2010-and-SQL-Reporting-Serv