Data-Aq is short for Data Acquisition. It is just recording what is going on so you can go back and look at it later. It is what you need to do in order to know what to change in order to make your motor run the way you want it. Just knowing what you want to try to get to isn't enough. You also need to know what it is to start with in order to know know how much to change it.
A tipical fuel map would be rpm vs map and have different values of volumetric efficiency. You will be able to sort the data you recorded and find out what the actual AFR was at one specific rpm/map value, compare it to the desired AFR and know how much to change the value in the table.
You can do the same with change in TPS vs time (aka dTPS/dt for you nerds out there). Compair the actual AFR to the desired AFR and make changes acordingly.
Recording spark advance vs. MAP, RPM, & knock count will be hard to do. There is some dicussion on how to record knock on the WBO2.com's yahoo email list that you can search for. If you are recording the inputs for the spark table (RPM vs MAP for the most part...), and know if it is knocking or not you can know if what is in the map is too low or too high. You won't know exactly how much need to advance/retard it but it shouldn't take long to get it close. You will need a dyno to get it right on (same with the AFR).
I'm sure you have (or will) read about doing data-aq from the ALDL port but I think the output is too slow to do any good.