Welcome to Science Buddies!
SciB has given you some excellent advice.
In addition, I want to suggest you to create a data table that includes the following: Volunteer, Trial #, Age, Maximum Heart Rate (bpm), Resting Pulse (beats per 10 seconds), Resting Heart Rate (bpm), Exergaming Pulse (beats per 10 seconds), and Exergaming Heart Rate (bpm).
For making your graph (bar graph or line graph), you can use this site http://nces.ed.gov/nceskids/createagraph/default.aspx
Note that important equations for your experiment are:
heart rate = (# of pulse beats in 10 seconds) × 6 and % maximum heart rate during exergaming = exergaming heart rate
maximum heart rate × 100