I have planned on writing my own tutorial, but due to lack of free time (it is a very sought after commodity), it never happened. There are however already a few tutorials and “101” type movies on the net, so if you are interested in playing with PI, it is definitely worth a look.
The best one I found so far is the one prepared by Eve University:
http://www.eve-ivy.com/wiki/index.php?title=Planetary_Interaction
The planetary materials and their use is covered by another subsection of their wiki:
http://www.eve-ivy.com/wiki/index.php?title=Planetary_Commodities
After lecture of those you should be ready for the 8th of June 🙂