ok here are some info i got for dyno runs:
1. Before dyno run, make sure your car is in healthy condition, no oil leak, no electrical problems. To be better still, do a compression check and leak check of your engine (I did mine) because these 2 are the basic check every tuned cars should do from day 1. From there dyno using different runs will tell what are the strong, weak and problems of the vehicles.
2. Choose the right dyno machine. Choose the dyno machine that practice SAE CF (ambient correction), so far only i been to, GTAuto and Speedworks are using, Links is using manual CF.
3. Choose a wideband dyno machine, as i know so far i tried GTAuto, because a wideband reading will give more accurate and detail reading from the dyno session.
4. Choose an experienced dyno tuner (sifus), someone who is experienced and I will not go Speedworks for some reasons.
hope this information helps. 2 cents on the dyno machines.