runners world is a good resource, check that out, it's all about form, do it right and it's way easier...
but if it comes down to it and your still on the fence check out two suppliments
Endurox excell
and
NO2
(in that order) also on test day pop a few (2) asprine about 45 mins before you start the run, it'll thin out your blood and make it easier for your heart to pump.
do as much as you can on your own then if you need it start taking the endurox about 3-4 weeks out, NO2 is something that you can take 30 mins prior and it'll work just fine...
if you get shin splints (which at your weight i'm sure you do) don't just ice them with a bag, IMMERSE them in ice water for 2 cycles of 10 mins in 20 mins out...one session of that will get rid of some pretty bad shin splints.
Good luck.
-RJ
unfortunately off the street, but working on a 2-Year CJ Degree (40% Finished).
Yea though I walk through the valley of no radio reception, with backup in excess of 40 miles away I shall fear no evil, for I am a warrior, for whom the ranchers have an affinity, and they can take the head off a gopher at 200 yards.