Hi Vonsworld, further to other replies, let me add something important for you to consider. Here in the UK, most stone fruits are being seriously affected by a disease called 'silver leaf', where a fungus attacks the plant and causes the upper and lower leaf surfaces to separate giving a 'silvery' effect, hence the name of the disease. Now these fungal spores seem to mainly enter the tree in winter through the cuts, so if you prune as suggested in winter, make sure you use a bituminous based pruning compound but I would suggest that you leave any pruning to when the tree is in leaf when this disease is less active and to be safe, I'd still cover any cuts with pruning paint just in case.
regards, Lannerman.