If you mean you want to know your resting heart rate, prior to exercise, you can either count the number of beats in 10 seconds and then times by 6 or you can just count the beats in 60 seconds.
Fit people tend to have lower resting heart rates (RHR), so in the low to mid 60's and unfit people tend to have a RHR in the high 80's to 90's. You will find as you become fitter, your RHR will reduce.
Now, for exercise to be of any good, most experts recommend your heart rate reaches between 65 and 85% of your maximum capacity. The way to work this out, is to take the number 220 minus your age and then the % you wish to work at.
So in simple terms, if you are 40 years old and you want to exercise at 75% of your max this is what it would be... 220-40 =180 x 75%=135. This means through exercise, you need your heart rate to rise to 135 BPM (beats per minute).
A good way of ascertaining how your fitness is improving, is noting your recovery rate. Your recovery rate means the time it takes for your heart rate to go back to it's resting rate after exercise. The quicker your recovery, the fitter you are getting.
I'm not really sure if this is what you wanted to know, but hope it's of some use.