There isn't anything you need to know in advance. You should be able to drop the car off and wait for it (AWE had mine done in an hour). Follow the scheduled maintenance intervals for your car and you might want to switch out your plugs to something a bit cooler when it's time. AWE said I didn't need to change anything on the car and to have fun with it.
As for how it will drive: It will behave stock when driving it easy but it's a whole other animal when you get into it. You'll have zero traction in 1st gear and it will fight for traction all through 2nd. The main difference you'll feel is the torque increase in the low to mid RPM range. It's a pretty big kick in the pants. To be quite honest with you, Im suprised I waited as long as I did to get this done. Knowing what I know now, I would've had this car chipped the first week I got it! (yes, it's that good).