Carol O'Meara, CSU Extension agent from Boulder explains fruit tree pruning in these excellent articles.
Pruning fruit trees, part 1: the basics, plus peaches
Pruning fruit trees, part 2: apples and pears
Colorado Master Gardener Volunteers gardening and blogging in Jefferson County Colorado. We work at the CSU Extension Office at the Jefferson County Fairgrounds. Call 303-271-6620 or e-mail your questions to mastergardener@jeffco.us