Heart Burn

Today was my cross training day and I completed 3 miles on the elliptical which took me about 49 minutes.  Again, I never said I was fast and my feet always seem to fall asleep on the elliptical! I thought about weight training and stretching while on the elliptical today, neither of which I do much of.  I have been lucky so far and have not had any major aches or pains from not stretching.  My problem is that I am not sure where or how to really stretch properly. Any suggestions would be greatly appreciated.  I was also talking to a friend in the gym today and he was asking what kind of weight training I had worked into my routine.  Well, I haven't really thought about that, what kind of weight routine should one be doing while training for a half marathon?  Any suggestions? 
I have had horrible heart burn all day and am thinking about turning in for the night even though it is only 8pm! Good night all!