Here is a great step by step for configuring and setting up SRS with ConfigMgr:

http://blogs.technet.com/b/mwiles/archive/2009/02/19/east-setup-of-srs-with-config-manager-r2.aspx

Here is a great article that details setting up the required permissions for SRS:

http://scug.dk/blogs/configurationmanager/archive/2009/08/13/configuring-sql-reporting-services-user-permission-for-configuration-manager-2007.aspx

Here is the SRS tag on Steve Thompson’s blog, lots of great posts here:

http://myitforum.com/cs2/blogs/sthompson/archive/tags/SSRS/default.aspx