how do i go about a dyno?

Hey,

A dyno is a dynometer, which is a machine. "Dynoing" your car typically refers to making a dno run which finds out the horsepower/torque/powerband/air-fuel ratio. They're somewhere around $50 a run depending on the place. A dyno tune is dynoing the car and tuning it specificly for your powerband, air fuel ratio, etc. to get good gains. You will need a chip to put the tune on. If you were to supercharge your car, you would definately need a tune or you risk running lean and thats not good.

Hope this helped a little.

Yep, if you s/c the GT you will have to run the highest octane you can or you will get that nice pinging noise we all dread called detonation. Detonation is caused by running lean. Basically there is gas that gets in the cylinder, explodes, and can ruin your car. If you add boost to an engine you will get detonation, its going to happen. Hence why a tune is so important.
A dyno tune is different from a dyno. You will have to have a chip to get a tune or have your stock eec reflashed. In short you make a baseline dyno pull, they look at what you have, remap timing and a few other things on your chip, plug it back in and see if it helped. It can take a few pulls to get it right so it can get pretty expensive. Most shops will charge you like 70-80 bucks for 3 pulls with a/f. A tune can be close to $500 counting buying a chip.

Lean is too much air, not enough fuel in the Air/Fuel mixture. Rich is the opposite. Generally, Lean is dangerous but also makes power. Rich is safer but makes less power. Optimum (chemically correct) AFR (air/fuel ratio) for a gasoline engine is 14.7:1, but typical N/A tunes are 12.5 to 13.0 to be safe.
Good, honest questions! Best of Luck!