There's only one thing I have to say about Imola: kerbs! They dominate the circuit - the way you drive, the way you set up the car - everything. Get them right, and you're sure to have a fast lap. Get them wrong, and you could find yourself spinning, losing time, or even damaging the car.
The main ones to watch out for are the kerbs at the top chicane - Variante Alta. This section is really critical for a good lap, so it's important to know what you're doing there. When you get them just right, they don't upset the car too much and you can carry a lot of speed through. But when you hit them wrong, you really know about it!
The important thing to remember is not to let them dictate all your thoughts on set-up. Sure, you can set up a car to be fast or at least comfortable over the kerbs, but if you do that you'll be losing time at other places on the track, so really it's all about compromise.
I was on pole at Imola last year, for my very first GP2 race, and I remember feeling a little bit surprised about it because we hadn't been fastest before the season. But suddenly, there we were at the top of the time-sheets!