Pruning a Peach Tree

I planted a bare-root Reliance peach tree about four years ago. Up till now, I've been trying to train it in an open vase shape with four primary limbs. Last summer it literally doubled in size moving from about 6' to about 12' or more.

I'm thinking that I need to keep this tree pruned into shape to enhance production and protect the structural integrity of the tree. But, I don't know much about how to do that. Can someone point me to a good information source about pruning peach trees?

Thanks,
Bryan

 

this thread names a good book on the subject: http://www.botanicalgarden.ubc.ca/forums/showthread.php?t=2311&highlight=pruning+book

also, I always have this one in my breifcase for reference: The pruning of trees. shrubs and conifers, George E Brown, Timber Press