A while ago I whipped up a guide called "Stats for a Hunter", where I discussed the "main" stats, such as agility and stamina, and their importance (or lack thereof) for hunters.
I had a couple requests to add to it with Attack Power, Crit Rating, and Hit Rating, and that has been my plan all along, so here we go:
Attack Power effects how much you will hit for with each shot. 14 Attack Power will increase your base DPS by 1. Oh, and Attack Power typically applies to both Melee and Ranged (unless otherwise specified.)
Now remember, one point of Agility will also give you one point of Attack Power, as well as some crit. This is why many hunters, myself included, prefer to gem and enchant themselves up for agility rather than Attack Power. However, as always, use your judgment. Many times an AP gem or enchant will give you much more raw AP than the Agi gem or enchant; at the expense of the crit that the agi will give you. A good example would be your two-handed weapon enchant. You are either going to want Savagery (+70 attack power) or +35 agility on it. Which one is better? ...well, it depends. I tend to stick with the agi myself, because I'm a crit fiend, but few people will fault you too much for Savagery especially if you are very low on AP for some reason (unless you are a Survival hunter, in which case you had better be enchanting for Agi! =P)
I did once write up my own thoughts on why I'm more of an Agi fan over AP, so feel free to take a look at that if you want more info.
Critical Strike Rating does what it says on the tin: it improves your chances to score a critical strike: an attack that does twice your base damage. At level 70, the chance to crit increases by 1% per 22.08 crit rating.
Now crits are delicious, not only does the crit itself do a ton of damage, but it lets you use Kill Command, it gives your pet a ton of focus (if you are spec'd for that), and your pet can in turn use that focus to score its own crits and proc frenzy/FI/etc. if you are a Beast Master. It's pretty plain to see why I'm addicted to crit.
Don't forget that agility will also get you some crit, although not quite as much as "pure crit rating". So it's sort of like the opposite of Attack Power. You've got Crit on one end, Attack Power on the other, and Agi in the middle. Agi is a nice middle ground, gets you a little of both, and scales with Blessing of Kings which is why so many of us opt to stick with Agi when possible.
So what's this crazy thing called hit rating that you maybe saw a little bit in old-world Azeroth but is all over the place in Outlands?
Well, hunters, do not underestimate the importance of hit rating.
You know when you shoot something and you "miss"? Yeah, you just lost a bunch of DPS as well as the chance for a possible crit which, as I said before, does a ton of great stuff. How can we fix this?
Here's a little background info. We are hunters, and our ranged attacks cannot be parried, blocked, or dodged. We can miss, though. By default, at level 70, we have a 9% chance to miss against a level 73 raid boss. That 9% chance can be reduced to almost nil with enough hit. It takes 15.77 hit rating points to gain 1%, so if we want that full 9%, we need 142 hit rating points. 142 is the magic number (the meaning of the life, the universe, and everything + 100 after all) and you want to get that or as close to that as you can get.
Hitting 9% more often is basically a 9% damage increase, which is huge. This is why we learn to love the hit.
Once you get to 142 hit, obtaining any more than that is useless and you can start focusing on other stats. Going over isn't going to hurt you but it also isn't going to help you at all. On the other hand, it might be good to be just a little over to give you a buffer in the event of maybe getting some awesome new gear with no hit on it. It all depends on how much min-maxing you want to do!
Oh, and there are some special things that can help you here, aside from gear. If you are a Survival Hunter, you probably put points into Surefooted, a talent which gives you a hit boost. Similarly, if you are a draenei, you have a slight increase to hit through your racial. In the former situation your hit cap is only 95, in the latter, it's 127.
Now you may be feeling overwhelmed at this point, wondering how to keep track of this all and how you will ever be able to balance all of these stats, plus the "initial ones", once you hit 70. Fortunately, it's not that bad! You can make clever use of gems and enchants to help boost yourself where you may be lacking. When in doubt when it comes to new gear, you can always install and use one of my favorite addons, RatingBuster, which will easily summarize for you all the pros and cons of some new gear. (Don't forget to take enchants and gems into account though-- I've done that before-- passed on something awesome because "Oh it's not as good as my current thing", then realized I wasn't taking enchanting the thing into account. x_x)
Well, that'll do it for now. As always, I love your comments and questions!