Hi OP, I have epilepsy since I was 3 and my heart goes out to you and your son, this will inevitably feel terrifying at the moment. The good news is that with a specialist and a bit of time things are MUCH more likely get under control than not. Things have come on a long way with epilepsy treatment since I was a child in the 70s. ☺ Epilepsy Action is, as an earlier poster said, a good source of information.
Some things that you might want to think about from the angle of the patient. Try not to mollycoddle him. Obviously you need to know that he is safe and in these early days that might involve always being at hand or having someone close by who can contact you and/medics. For what it is worth seizures feel and look far worse than they actually are. As long as he is getting a warning sign and acts on it -sitting down straight away, for example - then confusion and a headache are the most likely immediate consequences. Talk to the doctor about this. At it's simplest, if you think of the signals within the brain as music then a seizure is where part of the brain produces only white noise.
Despite what I just said about mollycoddeling, reassurance immediately after a seizure is always worthwhile. At that stage your son will feel confused and disorientated. I only mention this as my mother was great at the above and rubbish at the reassurance, but hey, no one is perfect!
Medication is much gentler now than it was when I was a child. It might take a few different tries, but the side effects are much smaller now.
A tip for your son, do not try to defy the seizures. Until they got the right mix for me I would always try to fight the seizures off. All that happened as a result was the tension built up inside me and the seizure ended up being worse. Rather too late in the day I discovered that if I just accept the aura is happening and 'go with it' the aura would not turn into a seizure. Not easy for a 9 year old to get their head round and not an alternative to medication but it is worth getting your DS to try to get into this habit.
For much the same reason I would be wary if ever you think he bottles up tension. I am basing this on myself and one other person with epilepsy, not medical records. My mother once observed that my seizures (in the 70s and 80s) were preceded by a few days of my being tense. I wonder now if tension relieving activities might have helped.
Last, and perhaps most importantly, you are not alone. 1 in 150 have epilepsy and there is probably a support group in a town or city near you. Epilepsy Action should be able to point you in the right direction, if not then your specialist will at least know where there is one. If he/she doesn't and there is an epilepsy nurse then he/she will. Best wishes to you and your son. 