The way it's supposed to work, they more your body is accustomed to cardio activity, the lower your resting pulse rate will be. This is because the stronger your heart is, the more it accomplishes with one pump.
Athletes (olympic type) have around 40-50. Moderately active people should have a resting pulse of 50-65. The average person has between 65-90.
Personally, mine is always between 45-55. Lowest has been 43 but I was half asleep. During a lesson at school it was 50.
[Edit] Also, the younger you are the lower it can be. Also depends on your weight and body composition but those are more in depth. I'm 15, 145lbs. Doctor says that for my body specs, 45 is just fine. (I'm not as active as most sports players in high school, so I don't think 30 should be dangerous.)

You cannot get your resting heart rate from simply sitting down on your bed and waiting for a bit. The best and most accurate time would be after waking up (from a full night sleep, not a hour nap), sitting up from your bed and checking then.

The previous poster is correct concerning heart rate and athletes. If you are physically fit (through cardiovascular activity), your heart becomes more efficient at pumping blood to your organs so it does not need to pump as often.

Hey,

I am very cardio vascular fit and my resting heart rate has been as low as 29 and i am not very worried, i think both are right the fitter u are (C.V wise) the lower your resting heart rate is, I tested mine one day by having a HR Monitor on the whole night and then looking at it in the morning, I also believe that if u test ur Resting HR about 3-4 days a week for months on end if u notice that one day it shoots up it can be an early sign of sickness. Something interesting to think of.