I was poking around some other SSRS blogs from folks here on the product team, and I found this post from Lukasz about troubleshooting Reporting Services.  It is a great overview of some of the guidance we have given in the form of whitepapers, KB artciles, and a bunch of other sources.  I highly recommend you give it a read and bookmark it so you can use it is your "playbook" when running into problems.