There are many different ways to set up your rope. First you need to decide what type of rope to buy. You can spend anywhere from nothing to $80 dollars on a ski rope. I suggest you spend a minimum of $35 and buy a sectional ski rope. These ropes have removable sections, some even have the rope lengths marked on the rope.
The standard ski rope is 75' in length. The first section takes 15' off, which leaves you with an overall length of 60'. Then next section is 7', leaving 53'. The third takes 6 more feet for a total of 28' off and a 47-foot line. There are on average another 4 sections that can be taken off, but we usually don't concern ourselves with those. Most pro wakeboarders will use a length between 41 and 60 feet. As a beginner, I suggest using a shorter rope, maybe even less than 40 feet, depending on the size of your boat wake and your boat speed.
There are also specialized wakeboarding ropes that are non-stretch. These are made out of polyethylene, called poly-e. There is a definite advantage in using a non stretch rope, because when you start jumping a stretchy rope will recoil during your jump and pull you down. A poly-e rope will be solid and not stretch, giving you the height and distance you try so hard to achieve.