Hi. The post is over a month old so my reply may not be needed, and although I'll try to simplify it, this may be confusing to the newbie, but here goes ...
Most big old full sized apple trees will not make much fruit without proper training, not only pruning. Many books seem to skip over the training parts and concentrate on pruning. Training involves manipulating the branches to grow where and how you want them to grow. Left alone, most apple trees will grow all of the branches straight up, which is what you don't want for cropping. Just pruning off these branches is a constant losing battle that never ends until either you or the apple tree dies. And apple trees can live several human lifespans.
Most apple trees only bear fruit on parts of branches that are lower (closer to the ground) than the node where the branch grows from the tree. So branches that grow straight up will only give you vegetative growth, not fruit. In order to induce the branches to fruit, we have to weigh them down. Note that this isn't necessary for compact spur (compspur) type apples, and will not work on the very few apple varieties that only bear fruit on the tips.
In the spring, on the large side branches, select nice thick flexible upright branches that are at least 1 year old. The longer the whip, the better. These branches I will call "Branch Type A". With twine, tie a weight or weights onto the tip of last years growth, not on this years growth if there is any yet. It will strangle the tip, but that's okay. I make weights using 3 ounce paper cups filled with concrete and a paper clip sticking out to attach the twine to. Don't put so much weight that the branch breaks, but put enough so that the branch starts to bend down. Sometimes twisting the branch a little helps it to bend easier. Weigh down branches every 6-12 inches or so, and prune off the other uprights. If a weight falls off, tie it back on.
Next spring, there will inevitably be a few broken A-type branches. Prune those off. On some of the A-type branches, there will probably be 1-year old side branches where the branch tried to grow back up. These branches will be "Branch Type B". Move the weight to the tip of the lowest B-type branch if it extends farther than the A-type branch that it is on, and cut the A-type branch back to this B-type branch. If there are more than one B-type branches on an A-type branch, select the highest B-type branch and prune it to a few inches higher than the highest point of the A-type branch. This will be solely an outlet for the vegetative growth that the tree wants. Prune off all other B-type branches on the A-type branch, leaving 1 inch stubs. As long as the A-type branch has an outlet for vegetative growth, these stubs will often grow spurs instead of more branches. Do not prune off any spurs.
Repeat this training/pruning every year as needed.
Within a few years the A-type branches will harden into place and the weights can come off. When the branches get wider than the space between them, thin them out.
With luck you should have a good crop within a few years.