Just make sure your tires are properly inflated (COLD) and are rated for redline RPM speed in 4th gear (or PCM speed limit if that's a factor). If you've never been to a dyno before, tell the operator and he'll run your car for you for sure. Most don't let any customers drive their cars on the dyno for safety/liability reasons. I got to run mine because the operator had to sit shotgun and read the manual wideband O2 readings (the one that hooked to the DynoJet software fell victim to a blown engine the day before). If the car is ready for a highway drive, then it's ready for a dyno run.
Basically, the car will be run normally into 4th gear and then go WOT from low (2000 - 3000 RPMs) to redline (or just short) in 4th for recording. They'll strap it down real good before it gets run (that will probably take longer than the runs actually).
Your ABS light may get set after your runs. Having two wheels moving and two stationary tricks the ABS computer into thinking the rear sensors are shot sometimes. It'll go away after a few days once the computer sees the rears moving again. Just remember, if that happens you don't have ABS (IIRC) when the light is on.
