Xtec Shooter, summed it up pretty well, but there was one thing that I'd like to add - when you do apply wax to your bowstring & cables, lightly work the wax in with a small piece of leather. This slight friction of moving the leather up and down the string will help the wax reach the inner strands of your strings & cables, thus further prolonging the life of your string.
One other thing that I would like to mention is that from time to time, check for any signs of separation of your serving. The sharp bends around the cam(s), or if you happen to shoot directly of the string, opposed to using some sort of loop, are two of the more prevelant areas for serving separation. And even if you are shooting some type of string loop, it doesn't hurt to remove your loop periodically to check for any separation that may lie underneath the knots of your loop - a few stock strings will have serving loose enough where you can actually shift it with just your fingers!
If all of this is caught soon enough, these areas can be re-served or repaired without any serious damage to your strings and/or cables.