One or more features must be turned on before this feature can be activated.

Scenario:
You are trying to activate Office SharePoint Services Publishing feature and get following error.

Error SP2010:
The SharePoint Server Publishing Infrastructure feature must be activated at the site collection level before the Publishing feature can be activated.

Error MOSS 2007:
The Office SharePoint Server Publishing Infrastructure feature must be activated at the site collection level before the Publishing feature can be activated.

Reason:
The publishing feature (Site Feature) is dependend on the Publishing
infrastructure feature (Site Collection Feature).

Resolution:
For activating the feature, go to

1. Navigate to your Top level site and click on Site Actions > Site Settings 
2. Under Site Collection Administration, click Site Collection Features
3. Click on Activate for Office SharePoint Server Publishing Infrastructure
4. Once that’s activated, Navigate back to site settings page of the site you was getting error.
5. Under site administration, click on Site Features
6. Now Activate Office SharePoint Server Publishing.

Done!!!