Tues-Thur-Fri-Sunday - run
Mon-Weds - stretching, strength, calisthenics
Saturday - yoga
Shin splints - don't try to run through them. Take it easy for a while, reduce mileage and read the article recommended above by Joe_h.
I started exercising to help my BG control. I was basically a couch potato before diagnosis eight years ago. Now I exercise for pretty much the same reasons as acidrock23.
A day without exercise is like a day without sunshine for me. And I exercise come rain or come shine.
As for overdoing it - listen to your body. If it hurts - STOP! Some mild discomfort or fatigue is normal. Some mild persistent soreness after exercising is normal. Constant soreness or pain, limited motion, sharp pains, pain on particular movement (e.g. it hurts when I do this) are signs of injury. Slow down, take it easy, apply ice/heat, see a physician. I'd also say that unless you're a competitive athlete, pro or amateur, or you're training for an upcoming event, over 90 minutes a day is overdoing it. But that's me.