I currently make a decent $600 monthly from adsense with printnpost.com and wanted to see what others are making and any tips they might have to increase it.

You should know, that you aren't allowed to publish your AdSense Earning. Read the Terms of Use

Some previous discussion about this here from a couple of years ago:
http://blogoscoped.com/forum/364.html

hebbet, you ARE allowed to publish your AdSense earnings (though not your clickthrough rates or earnings per impression).

From section 7 of the AdSense Terms and Conditions (United States version):

"You agree not to disclose Google Confidential Information without Google's prior written consent. "Google Confidential Information" includes without limitation ... click-through rates or other statistics relating to Property performance in the Program provided to You by Google ... However, You may accurately disclose the amount of Google’s gross payments to You pursuant to the Program."
https://www.google.com/adsense/localized-terms