Taking your own blood pressure with a blood pressure monitor is a simple and reliable way of getting a blood pressure reading. Make sure you're sitting comfortably with your arm relaxed and supported on a table just in front of you. You'll need to wear loose clothing so that you can roll up your sleeve. Roll up the sleeve of either arm and slide the cuff up to your upper arm so that the bottom of the cuff is just above your elbow. Wrap the cuff snuggly around your arm, making sure that you can fit two fingers underneath. The tube from the cuff to the monitor should be running down the centre of the inside of your arm. When you're comfortable press the start button and you'll hear the monitor start up and feel the cuff around your arm begin to inflate and tighten - this shouldn't be painful, but if you've wrapped the cuff too tightly then just press the stop button and loosen the cuff before trying again. After a short period the monitor will show a reading for your systolic and diastolic blood pressure as well as your pulse rate.
Simply record the systolic figure (the higher of the two numbers) and the diastolic figure (the lower of the two numbers) into your vital statistics.