SharePoint 2010 Logs (location and viewing)
If you are a SharePoint 2010 Admin, sooner than later you will run across issues that require debugging. You may struggle with configuring a service in Central Admin or just receive a report from a site collection or site admin that they encounter an error message with a funny correlation ID and a request to debug using SharePoint Foundation. Your best friends here are the SharePoint 2010 log and a good log viewer.
SharePoint 2010 logs are located in the SharePointRoot\logs folder. SharePointRoot is also called Hive 14 (as in Hive 12 in 2007, and probably they skipped 13 on purpose). The path to SharePointRoot is C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14 and logs are in C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\logs
For a log viewer, the traditional tool is ULS viewer is a great tool (you can use Notepad if you prefer to suffer) and is available for free from http://archive.msdn.microsoft.com/ULSViewer.
ULS can read logs from their location (files), from the clipboard or in real time (record, pause). It has powerful filtering and several display options (see an article that explains ULS). You need to run it as Administrator.
Other log viewing tools exist like http://sharepointlogviewer.codeplex.com/ and a recent tool at http://splogviewer2010.codeplex.com/
It should be noted, though, that some errors may not make it to the SharePoint logs – especially administrative tasks. In such cases, you should also check the Windows server event log and the MS SQL server logs.