Many a times you feel struck by SharePoint throwing some error message. The message in most cases may not be descriptive enough to understand the cause.
The logs can be of good help in that case:
By default the logs are created under path: <drive>\Program Files\Common Files\Microsoft shared\Web Server Extensions\15\LOGS.
For SP 2010 it would be 14 instead of 15. For SP 2013 its 15 and accordingly for older or newer versions.
Now under Monitoring, open the option ‘configure diagnostic logging’.
Now you reach the ‘Configure Diagnostic logging’ page, scroll little bit down you should find an option to set the logging path:
Keep it as it is, or change as you want it to be.
Reading Logs will save you a lot of time and help diagnose problem quickly. Make a habit of using the logs.