also, make sure you're observing
proper form when you run.
most ppl run the wrong way: they hunch up their shoulders, pump their arms stiffly, breathe through their mouths, and run on their toes.
when you run, keep your back straight, your abs firm (not squeezed tight), and your shoulders down, loose, and open - don't squeeze them up around your ears, this aint' a trap exercise. keep your head in a neutral position: chin pointing forward, not sticking up or laying down on your chest. breathe in through your nose and out through your mouth: this prevents your mouth and throat from drying out and you won't hyperventilate from gasping. let your arms swing naturally with your stride and again, keep them loose and limber.
the most important thing is make sure you land on the heel of your foot and roll (not push) off your toe. if you're running on your toes, you will, perforce, experience calf pain. if you push off your toe, you'll likely get shin splits.
oh yeah - make sure you're using "running" shoes, not cross-trainers, joggers, skateboard shoes, etc. the genuine articles are all constructed very, very differently and can have a huge impact on your running ability and foot health.