Not sure what fruit trees you have but if you have any mango trees here is a website(Australia I think?) that gives some pretty detailed techniques on how to prune mango trees...Hope it helps.

Here is a link that might be useful: Pruning Mango Trees

Try to never prune more than 1/3 of the growth off a tree. Rodale's has some great books which cover pruning. I imagine surfing on edis.ifas.ufl.edu would have lots also. Some trees its beneficial to prune for an 'open center', some not, depending on how low you want to go. Like if you need to mow under it or not. I usually try to discourage my fruit trees from going vertical beyond 8 or 10' tall, at least the ones which have gotten that far.

Gary