From the Magento Admin Panel: Navigate to System → Configuration and under “Advanced” in the left side menu, click “Developer”. Under “Log Settings” set “Enabled” to “Yes”. Make sure it is enabled within the store's scope as well.
From the Magento Admin Panel: Navigate to System → Configuration and under “LITEMAGE CACHE” in the left side menu, click “LiteMage Configuration”. Under “Developer Testing” set “Enable Debug” to “Yes”.
system.log will now be generated in magento_installation_directory/var/log.