Chrome has some built in tools. If you open up the element inspector, focus on an element, scroll to the bottom of the right hand column (where the CSS/Metrics/etc are), you should see a drop down section that says Event Listeners. This can help some...
Often I find it easier to just add event listeners to some DOM element via the console and seeing if it responds. Or I throw in debuggers in various places (before setting up the listener, and inside the listener's callback). The problems I usually run into is the selector I think exists doesn't or the event gets bound too early and misses the selector.