Once you reach level 62 and learn Steady Shot, it's time to start getting a firm grip on this thing hunters must learn called "shot rotation." If you don't - just casting your shots willy-nilly, as soon as they come off of cooldown -- you'll end up wasting a lot more mana and doing a lot less damage than a hunter who has his or her shot rotations timed right.
The video embedded above is a handy example of two basic shot rotations which we'll look at in more depth here, and it can give you a basic sense for how the timing of all this is supposed to work. But if it still looks a bit confusing, fear not: today's Scattered Shots will help you to make your shots less scattered and more organized, with helpful charts and fundamental knowledge about how to do this rotation thing. It really ain't that hard -- just a bit of info can get you pointed in the right direction, determining the rotation which is best for you.
Behold: The Inevitable March of Time. This baby is that irrepressible force moving the entire universe forward through the 4th dimension, bending a little around planets and stars, and getting totally warped out around black holes:
Next, meet Auto Shot. Don't look down on this one just because he doesn't have a fancy casting bar in the default interface. This is your source of mana-free damage, coming to you at regular intervals depending on the ultimate speed of your weapon. Once you get him going, he keeps on marching and doesn't stop till you tell him to, or until your target is dead.
The actual Auto Shot casting time is a tricky thing. It takes 0.5 seconds to cast Auto Shot. Usually, this half-second is included within the last little bit of the time between Auto Shots, as pictured above, but if you are doing something else during that time, your next Auto Shot will be delayed. It may be helpful to think of your weapon speed minus 0.5 seconds as your Auto Shot waiting time, and then the last 0.5 seconds as its casting time: during that half-second you must be standing still, casting nothing, or else the next Auto Shot won't go off. Half a second doesn't sound like much, but if you don't respect it, the delays it causes can add up over time and reduce your damage. (For more about Auto Shot, look here.)
Finally, we come to your special shots, most often used in healthy shot rotations: Steady Shot, Arcane Shot, and Multi Shot.
Note how the damage from Steady Shot comes at the end of its 1.5 second casting time, whereas Arcane Shot hits instantly (followed by a 1.5 second global cooldown), and Multi Shot hits after 0.5 seconds (which is part of the 1.5 global cooldown). This is important for your timing, because Steady Shot will wreak havoc on your Auto Shot timing if not used carefully, as you can see in this example of a botched up shot rotation below:
Now that we're feeling inspired, let's add Multi Shot to the mix:
Up to now, we've been working on the premise that you have a relatively slow weapon - but some hunters, especially Beast Masters, have lots of haste effects either on their gear or in their talents, which can change this setup dramastically. Supposing your ultimate weapon is hastened all the way up to about 2 seconds, for example, that leaves you without enough time to fit in those Arcane Shots or Multi Shots, without unhappily delaying your Auto Shot as well. In this case, it's best to revert to the good old standby rotation: "Auto -> Steady -> Auto -> Steady."
Whichever rotation you choose depends on your personal play style, of course. You may also find yourself in a situation where you want maximum damage and you don't care about mana-effeciency, in which case you can rotate something like this:
[No Elitist Jerks were harmed in the writing of this article -- Thanks for the inspiration!]
Edit: I corrected the Auto Shot graphs, and added lots of explanation to help clarify the tricky nature of its casting time. Hopefully now it is not only more accurate, but easier to understand as well.