Shall I compare hunter leveling to a summer's day? It is as long and as sweaty. Oh, how many days ago it was that we began the journey from level one to level seventy. How the weeks and months have passed us by! Do we forget the long stretches of time casting the same repetition of spells over and over? Can we disremember the times we ran out of mana while our pet took all the damage on our behalf? Indeed some of us have gotten bored in this journey across the desert of time, and have charged forth into the enemy to do melee damage.
Dearest hunters, do not despair! Do not raise your two-handed axe in anger at your enemy! Do not give into the temptation that speaks within your heart: "must... charge in... must... use eviscerate!" Hunters are an endurance class, not in the time it takes us to level, but in the way our leveling doesn't change unless we push ourselves to the limits, bend and break the boundaries of space and mana. Take heed, lest ye give into complacency and huntardiness! Beware, lest ye give into your non-hunterly instincts and rush into melee range of your enemy with as much effectiveness as wet noodle!
Consider, on the path from level 30 to level 40, all the new spells which you may add to your arsenal of death and destruction, and decide how you may use them in your quest for ever-more interesting forms of damage-by-distance.
But wait -- before we continue, let us remark for a moment upon one of the spells which you do not yet have: Steady Shot is the spell you must thirst for, the spell which will make things so much more interesting once you reach level 62. Steady Shot will allow you to begin consideration of shot rotations and start having more dynamic gameplay. In my opinion, Steady Shot should fit in at about level 30 or 40 -- level 62 is much too long to wait for it, and the mere 8 levels between there and the level cap do not give you enough time to really get a firm grasp of what shot rotations are all about, especially after having gone so long without them all this time. Blizzard! Heed my call! Make leveling 30-60 more interesting!
There, now that's taken care of, let's have a look at what we do get at this point in the game:
Level 30: Behold! Feign Death is the spell most like a "get out of trouble free" card in the World of Warcraft. You should use it in conjunction with a threat-measurement addon in order to practice faking your death just before your enemies turn to attack you rather than just after they do so. While you are on your own, it may seem as if there is no difference, since the enemies will just go back to attacking your pet either way, while you are with a group it may make all the difference in the world. If you feign death before getting aggro, the enemies will continue to attack the main tank, but if you use it after getting aggro, they may rush off to attack a healer or some other squishy person instead! This would be bad.
Having said that, one thing which can be kind of fun is using Feign Death along with other tools in your bag full o' hunter's tricks to play yo-yo with your enemies. Try and kite them around (one at a time) and make them spend most of their time running back and forth between you and your pet rather than actually doing damage. Doing this can help you get a good sense of how to control your threat as much as possible.
Also, be aware that Feign Death usually doesn't just fail for no reason the way Vanish sometimes does, but it can be resisted. In addition, if you happen to be turning your character one way or the other while trying to Feign Death at the same time, the Feign Death cooldown will start but the ability itself will not activate (since turning or moving in any way cancels the Feign Death effect). This last one is kind of an odd doozy that left me confused (and dead) lots of times before I figured it out. I have to keep my Feign Death key away from my movement keys so that I don't accidentally use them both at the same time.
Aspect of the Beast is... mostly useless, except that it has a snazzy sounding name. It's only real use in combat is in PvP, when you are hiding behind a pillar or something and you don't want some other hunter to find you. Since we don't have any form of stealth (yet), the element of environmental obscuration is essential for this to work at all.
Also don't forget to get your mount now! (Yay!)
Level 32: Flare is kind of handy if you are trying to do one of those quests where the enemies you have to kill are stealthed. With most other classes, you'll have to just run around hoping to either spot the enemy first, or else to run close enough that they spot you and start attacking. But with a hunter you can cast a flare to check out a spot without having to actually run there. The downside to this is that you might easily hit a spot with no stealthed enemies in it and have to run around for 20 seconds anyways while Flare's cooldown wears off.
You also get Track Demons at this point. It's useful for tracking demons. Use it when fighting demons, and wishing to track them.
Level 34: Explosive Trap can be a bit of challenging fun to use well. I wouldn't recommend using it in a group very much unless you have a good AoE or multi-target tank (such as a paladin) who can easily hold the aggro of all the enemies you will damage with it and keep them in one place long enough for the trap to have its full effect.
You could also use this trap to test your multi-target pet-tanking skills. This skill could be especially useful once Wrath comes along and gives hunter pets their very own tanking talents.
Level 36: Viper Sting is a great spell, though it's mostly useful in PvP situations. Check out the awesome Scattered Shots post by Daniel about how to use it well.
Level 38: Sadly, there are no new abilities to play with at this level. Please move along.
Level 40: A week ago, I would have been congratulating you on being able to get your mount once you reach this level. But by now you should have had your mount for a long time already. You also get Aspect of the Pack, Volley, and Track Giants (as if giants needed tracking) at this level, but we'll leave those for another time, another post.