I use this guide: http://reprap.org/wiki/Triffid_Hunte...ibration_Guide

The stacked calibration cube is painful but does show all the problems that you have and help you get an idea how to proceed.

FYI - my latest printrbot had a link to a firmware file and a configuration file for slic3r. After installing those I didn't have to do anything else to my printer except set an offset specific to autoleveling. The slic3r recommendations, especially, was a huge help to getting up and going quickly. Not sure what printer you guys built but MakerFarm may have the same.

Have fun!