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Go to their website (noted above), download, and install their demo. It tells it all. Big download, but well worth the time and trouble if you are considering one. :yesnod:
After you read that and get a feel for whats going on, then you will want to hook up your OBD-II scanner. The site posted here about the parameters is a good start for what you want to observe.
I assume you have a MAF Translator and are looking to tune. Remember that your primary concern for a while will be montioring your Long Term Fuel Trims during non WOT operation. These will be adjusted with the BASE setting only at first.