Biggles,
Don't worry about it, you will be fine once you start to drive.
During Aeros training I felt sick occasionally, but the more you practice the better it gets. After a long break from Aeros, I went up in an Extra and when I got back re surfaced the apron with my lunch. All you need is to work up to it slowly. If you have some training to do, try 30 minute flights initially and build up to longer ones if you need to. Try to fly more than once on any day as well if you can. Two 30 min trips might be better than one hour long trip for instance.
Things that I found made it worse;
Heat
Tension (shouting instructor!)
De hydration
Tiredness
Disorientation
Exhaust smells
Hunger
You might find that alcohol affects how sick you feel as well. If you are a passenger than a hangover or consumption on board will likely make you feel worse. Of course, if you are flying yourself, then that shouldn't be a factor.
My Dad found Polo mints a real help and my Cousin used 'sea bands' with great success.
In my day to day job, I have never had a problem, either in turboprops or jets (touch wood!). Don't let it stop you.
Apparently Nelson was sick on every voyage!