I don't know much about the Ukraine, but given the growth of tourism in Eastern Europe as a whole I would expect that more and more backpackers are including Kiev on their itinerary..Although I imagine you would be able to see evidence of that yourself.
Working in a hostel is a great way to learn more about the industry, but more importantly if you like the work.. I would also encourage you to do some travelling and stay in a few different hostels..This will give you an idea of what backpackers will expect you to offer in your hostel. Or try checking out some hostel websites. I think the best hostel I've stayed in was in Krakow Poland.. www.nathansvilla.com (when I stayed there it didn't have the bar)..