I'm 16 and have biked casually for most of my life. Last fall, I got into cycling and I'm looking to get into a couple road or MTB races this summer. What should I be looking for in terms of distance and intensity? I seem to be blessed with pretty good endurance but little in terms of sprinting abilities. I'm in decent shape; I cross country ski a lot and run and bike in the spring, although in the spring I have baseball, too, so I can't endurance train a heck of a lot. Any ideas are good.