This post I am about to do is on a sprinting start and the technique to bursting out of those blocks as quickly as you can.
You must begin in your blocks in a crouched position, with your back knee on the ground and all your weight resting on your fingertips. When the 'set' is called by the offical you bring your hips up so that your body is in an upright position. Be alert for the 'B' in the 'BANG' and burst out of the blocks at that point. Your reaction time is vital at the start of the race.
From your first 10-15 metres of the race, your aim is to stay low, pumping your legs powerfully, keeping your eyes and head down towards the ground and accelerating powerfully.
When you reach about 20 metres in the race you should gradually begin to bring your body into an upright position.
By 30 metres you should be running at your full speed.