Problem: Magento does not output log files
Context: New Magento Install
Solution: Turn them on in Admin
In Magento admin go to System->Advanced:Developer->Log Setting.
Set Enabled to YES.
Still nothing will happen if there are no log messages. The log directory won’t exist, nor the log files until the first time something is output to the log. Magento doesn’t really log much, so you should log something.
To make sure it works add this line to the end of index.php
Mage::log(‘Does this work’);