You can get a SharePoint error using the correlation ID (GUID) by running the following command in the SharePoint PowerShell.
get-splogevent | ?{$_.Correlation -eq "<GUID>"} | select Area, Category, Level, EventID, Message | Format-List > C:\Awesome.log
For more information see: http://technet.microsoft.com/en-us/library/ff607589.aspx.
