re: About to take on more responsibility at work, best ways to approach a raise...

I had this occur just a month ago. A coworker left giving me his responsibilities on top of mine. I told my boss that I was very comfortable with working for my company and my environment, but I had seen the numbers of what others were making in my field and that I was going to expect increased compensation. That was all it took and he pulled me in about a week later informing me of a 14.5% salary increase.