http://brentertainment.com/2012/02/28/contextualizing-your-symfony2-application-with-the-service-container/

Installing SonataAdminBundle for Symfony 2.1 with Composer Exceptions thrown by SonataAdminBundle and how to fix them Getting started with Symfony 2.1, SonataAdminBundle, FOSUserBundle and SonataUserBundle Symfony 2.1 : ACL, SonataAdminBundle, SonataMediabundle, SonataUserBundle and FOSUserBundle Symfony 2.1, SonataAdminBundle, SonataMediabundle, SonataUserBundle and FOSUserBundle : a good project base Symfony 2.1 : Customizing SonataAdminBundle

http://www.symfony2cheatsheet.com/