i workout first thing in the morning as well. i'm usually at the gym by half six which means i wake up at 445 am!!!
i know that sounds insane, but that is absolutely THE ONLY way that i don't make excuses to avoid going.
i actually eat both before and after my workout. since there is so much time between the time when i wake up and the time i actually get to the gym, i usually eat a yogurt or some cottage cheese and half a piece of fruit. these are the only two things that i've found that give me enough energy to get through my workout, but that don't weigh down my stomach. anything heavier than that and my stomach starts doing flip-flops while i'm on the treadmill. once i'm done with my workout and at the office, i eat a "proper" breakfast at like half 10.