My Philosophy about training a 4x100 relay team works for me but may not work for you. First I believe that your athletes should start fooling around with the baton passing as early as October. During this time they should get a taste of what the relay and the baton feels like. For the coach this is a good time to find out who can pass and take a stick, and who can't, plus this also gives the coach time to teach his/her athletes how to pass, and take a stick with either hand. I usually start doing full 4x100 practices during the late part of the indoor season (if weather permits), I will usually incorporate it in to our speed work days.
SETTING UP YOUR 4x100 RELAY TEAM............
1st leg- Should have a great start, good speed a the strength to run at least a fast solid 150m.
2Nd Leg- Must have very quick acceleration, and be a strong straightaway runner ( this leg is sometimes run by your best 400m runner if you don't have 4 solid short sprinters). Some coaches run their fast athlete on this leg.
3rd leg- This leg is usually your best curve runner. This leg should also have good pick-up speed and be able to hold or increase a lead. Depending on the type of athlete you have on the anchor leg(4Th leg), and your competition will sometimes determine the type of sprinter you run on your third leg.
4Th leg- Should have excellent acceleration, and very fast closing speed, and must have the heart of a warrior(this leg does not always have to be your fastest leg, many times they could be the 2Nd or sometimes even the 3rd fastest leg ,as long as they posses the first two qualities, and you have super sprinters on the first 3 legs)