Apple tree trimming

Hello everyone, my name is Jasson(pronounced "Asan") and I am brand new to Permaculture. I attended the convergence in Seattle this month and was blown away. "This is what I'm talking about", I kept telling myself... it resonated right away. So, hopefully my questions will not be too remedial and if they are I trust you will tell me to get lost. After attending a talk by Paul I get the idea he would if that was the case
So I have an apple tree in my front yard that needs trimming badly and I'm not sure who is really qualified to do the job correctly. I had a couple guys trim it a couple years back and someone told me they didn't do enough to it. It's been slowly decreasing it's yeild year by year and I'm not sure if it's because it hasn't been trimmed right and frequently enough or if Apple trees just naturally do that over the span of their life.
I'd appreciate any input or refferals you might have for this situation.
Thank you, and I'm glad to know this forum exists because it's a great resource.
Jasson

apple's need other apple tree's nearby for pollination I'd try to get another apple growing on the property just so I wasn't out of luck when the orchard down the road got paved over.

Are you still around JayZ?  Apple trees produce fruit from spurs.  New spurs form every year.  A spur produces for about 20 years.  Branches need time to age and produce spurs.  Study your tree.  Identify the spurs.  There is lots more to say but that is at the heart of fruit production.

Have you tried reving your tree? That can help a lot.
A general rule for fruit tree trimming is to prune not more than 1/3 of the total canopy. To give you a good idea of what a properly pruned tree should look like; Hold your hand out flat in front of you palm side up, next bring all of the fingertips up and together above the center of your palm, as if you're supporting an invisible tennis ball on your fingertips. Now, your fingers represent the major branches of the fruit tree , and you will notice that none of your fingers crosses your palm but instead are vertical or nearly so. This is a handy trick that I use when I prune peoples trees.
The steps of tree pruning:
1) Cut all the water sprouts,
2) Cut all the "crossers". These are limbs that cross or grow into the open space (remember your upturned palm and the invisible tennis ball?) in the center of the canopy.
3) Cut limbs that cross or block the sun of fruit bearing limbs.  
Now if your trees have not been pruned in some time then you may reach the 1/3 limit before you get past #2 or even finish this #1. So the next general rule is that the top (canopy) feeds the bottom (roots) and the bottom supports the top. When you break the first rule remember the second, and that your tree will go a little crazy when there is not enough food for the roots. The tree will try to fix this problem by growing a lot more water sprouts (your tree may turn into a bush!). There is a fix for this out burst of water sprouts but it is not something that I would advise a novice to do unsupervised.