I've been on Accutane before. It was administered by a doctor with routine bloodwork. Whether you are doing this yourself or with a doctor, I hope you are getting your blood checked regularly. Do not use gear or alcohol on Accutane (I'm sure some alcohol would be fine, but you might as well stay away altogether).
What to expect (from personal experience): you might not notice anything for a little bit, but the your skin will get extremely oily for a period of time, then it will get extremely dry and will peel like crazy. When you get to this point make sure you have plenty of lotion because it gets nasty.
Also, if you start to experience symptoms of depression, talk to a physician immediately. Don't do anything stupid.