In this post, I am sharing links to some TechNet documentation which have helped me a lot in the troubleshooting process. They are worth adding to web browser favorites and to the Resources list in SharePoint Central Administration website.
Events and error reference (Office SharePoint Server)
Account permissions and security settings - This article describes Microsoft Office SharePoint Server administrative and services account permissions. It covers the following areas: Microsoft SQL Server, the file system, file shares, and registry entries
Files and permissions for Office SharePoint Server 2007 - This article lists the detailed minimum file permission settings for folders and files created when you install Microsoft Office SharePoint Server 2007
List of rights (Office SharePoint Server) - In this article: List permissions, Site permissions and Personal permissions
Special directories and storage locations (Office SharePoint Server) - This article lists the folders and files that are used by Microsoft Office SharePoint Server 2007