Take a warm up jog, do some quick, light stretching.
Then do 4 leg kicks, 2 for each leg, trot out 10 meters. Then do side lunges, hold each side for 3 seconds, and do each side twice. Then trot out for another 10 meters. Then do right over left, and bounce stretch and count 1-2-3 for each bounce, and switch. Do each leg twice. Trot out 10 meters. Then do jumping side lunges, 10 times, so 5 for each side. Then trot out the last 10 meters.
After this, if you want to do some quick stretches for any specific muscle group, do so, holding the stretch for 10-15 seconds.
Then do condensed warm up drills. High knees, heel kicks, sprinter's jog, A skips, B skips, and strides and get outs. These should be 'condensed', so only do them for about 20-40 meters. You don't want to wear yourself out before your race. If you can, get in some practice block starts while the other races are still going on.
Keep your sweats on at all times. This means take them off only right before the 100 and put them back on right after the 100. This is so your muscles are kept warm.
Oh yeah, and don't forget to always do a cool down lap. Just a jog around/across the infield will do it.
