How does this heart rate monitor work?

Taking advice of many who recommend a heart rate monitor to improve your running, I bought a monitor several months ago. Fortunately, I got pregnant and was able to put off the idea of running for performance for several months. However, now that I am not pregnant and have no desire to go down that path again, I figured it was time to try this heart rate monitor. So, I go through all the effort of setting it up (the basic information) and I even read the manual. I think I tried using it a couple times, but the interval beeping wasn't loud enough for me to hear over my ipod so rather than take it out when I go for a run, I look at it and think: "I really need to figure that monitor out" and go out with my trusty timex.