With my heart rate monitor I completed a fitness test that showed me what my maximum heart rate is. Then I learned about 5 "zones" in which I can workout. The levels are different percentages of your maximum heart rate. For example the level 1 zone is the least strenuous. Your don't burn as many calories. Zone 5 will push you closer to your maximum heart rate. For the best fitness results, it is best to workout in the different zones throughout the week.
I am really excited about my new "toy". I have been logging calories according to what different websites and fitness programs say. I am always curious as to whether the cardio calories that I'm logging are accurate. Now I don't have to wonder :) This is perfect because myfitnesspal.com, which is the online service I use to log calories, urges users to eat the calories they burn. I don't want to log too many calories because I don't want to eat calories that I didn't burn. I also don't want to log too few calories and not get credit for the hard workout ;)