its been said before but for sprinting you need muscle, the explosive type, take a look at sprinters compared to middle/long distance runners.
so any strength building program will help, do a search on the net theres loads of theories and programs, start with a simple one first as anyone new to training will make good gains on just walking to the gym from the car ! ... but essentially for lower body you want to be doing squats, with a rack rather than any static machines or a smith press (they both limit your movement), dead lifts for the hamstrings and lower back, you need to make sure its balanced for quads and hamstrings. start with a light weight and work on technic first as doing them wrong can mess your back up, always ask someone if your not sure. for any diving people out there you need good shoulder and core strength aswell, so do some upper body work.
stretching, no-one likes it and not many do it but plenty of that aswell, especially before any games, the adrenaline's going and your more likely to pull something trying the extra bit, or flying into a bunker. and no-one likes to go fishing for a snapped Achilles.
the beep test is an excellent way to measure stamina, but wont really tell you if your faster ... the only way to do that is go down the local track and time a 50/100 meter run ..