I'm pretty hopeless at this shit myself so feel free to completely ignore my so called advice! I've had "relationships" with a few co-workers and I wont lie they've never ended pretty (but I think that has more to do with them being assholes than anything else)....its risky coz if things don't work out your kind of stuck in an awkward situation. But in my personal opinion, no matter what the outcome, I find it's always just best to be honest, just tell the girl how you feel, if you really like her then it's worth the risk right?? Hope it all works out!
Bob