Sunscreen spf 30 or higher, eucerin is a good one, it will help calm your face and lighten the dark marks. Either way, if you are going on Accutane, you will need a sunscreen period! Lots of water, your skin will be drying out, other than that, your multivitamin and your good to go.
When I was on it, I had to go once a month for a blood test, to make sure my liver and kidneys were in check. I was on it for nine months. I have never had acne again! I tried just about everything, before this, to no avail...
proactive etc.
Good luck and listen to your doctor's advice!