If you don't already have postgres intalled, then you don't need to know anything about it - just install the PT3 with postgres version and it should do it all for you. Where are you up to - do you have PT3 installed?
Open the ring game stats window, go to the Game Notes tab and click the first little "g" button next to this data section and it will graph the hands/$. If you have a huge number of hands to graph, use the second "g" button to show a more readable graph.