Sprinting, Acceleration

get into the gym. do squats, deadlifts (only once you have been taught the correct form), and walking lunges. Do those and you will be set

Exercise of the Week - Modified Tricep Dips
I'm a big fan of tricep dips because, not only do they work the back of the arms (or the 'boing' as my grandmother fondly calls that area), but they also involve the shoulders and the chest as well. The problem is, some people can't do this exercise because of shoulder and/or wrist problems. This version is done on the floor while holding onto weights, which can alleviate some discomfort in the wrists. Also, because you're closer to the floor, the range of motion is shorter which can add some protection for the shoulder. But, because of that shortened range of motion, the move is a little easier than traditional dips on a chair or machine. To take care of that, I've added a leg lift to the move to increase the intensity.
The key to making any tricep dip work is to use good form. Dips can often put the shoulders in an awkward position, so if you have shoulder or rotator problems, you may want to skip this move. To keep your shoulders protected, try not to move the hips too far away from the hands (when doing this move as shown or on a chair) and only lower down until the upper arms are parallel to the floor. In this case, you'll only be lowering down a few inches.

Do it right: Place dumbbells on the floor next to the hips (try to use weights that won't roll or use pushup bars). Hold onto them with both hands and push the hips off the floor. Extend the right leg straight up (or slightly bent) and bend the elbows, lowering the hips until they just graze the floor. Contract the triceps and push back up and repeat, keeping the leg up for 8-16 reps. For the next set, switch legs.

Dude you are still young. Disregard all the posts above. You need to spend time developing the fundamental skills of training so when the body stops naturally improving your biological systems (speed, strength, endurance etc), you are in a position to utilise training programmes effectively and perform exercises with absolute tehcnical and mechanical perfection. No one will ever a youth or junior champ but everyone remembers Olympic champs - it is a long process of physical development. By being very skillful at multiply training programmes, you can put yourself in an excellent position to be very trainable.

A few questions on the above response - where did 10 week plyo programme come from and how will this alone improve sprint performers strength? What role does the calves play in the action of sprinting and what is the implication of strength training them alone? And finally how does this all fit into a 12 years old programme?