SharePoint ULS Log

ULS: Unified Logging Service

Location:

SharePoint logs are located here by default:

C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\LOGS

ULS Viewer tool: http://ulsviewer.codeplex.com/

Configure logging level in SharePoint:

http://technet.microsoft.com/en-us/library/ee748656.aspx

A hotfix for Sharepoint Shared Services:

http://code.msdn.microsoft.com/KB976462