The title pretty much says it all. I'm leveling a hunter and really enjoying it. He's lvl 47 right now. When not instancing I'm running around gathering herbs to level his alchemy. He has all the BoAs items (thinking about getting him a 2nd swifthand of justice). So my question is – what advise would you give me? As far as mods or anything a new hunter would generally overlook. Any advise is welcomed, thanks.
Beyond Omen, I don't think there are really any addons you need to worry about. One of the hardest aspects of being a lowbie PvE hunter is managing your threat.
Beast Mastery would be my recommended spec. There's really no reason to spec MM or SV unless you plan to PvP, -or- you want more of a challenge. A BM build will make leveling a breeze, plus you'll be harder pressed to pull aggro in groups, should you decide to do some dungeons along the way.
I'd use a bear or croc for the PvE solo stuff, and a wolf, cat or raptor, when hitting instances.
Since you're 47, you may want to have a look at this post for some ideas: https://huntsmanslodge.com/staging/6262/diy-49-twink-hunter.htm
I highly recommend you look at the build I have listed in there. It's fantastic for solo-leveling, but also terrific for groups as well.
Lastly, don't be too pre-occupied with DPS at these lower levels. We can do well, but Mages can usually rock our face, as can Locks.
Seconding everything Gar said, and adding on a few long-forgotten talents that hunters used to be known for, and I think may become more desired in Cat:
Learn to kite. Any angle, any mob, in any direction, using just yourself and your pet. It's a hell of a challenge. Start with an equal-level mob, kite it a short distance, then go for the kill. Make the distance longer and longer and longer, and move up a level or two higher than you. Next thing you know, you're kiting dragons to Orgrimmar and the Fel Reaver to Shattrath. (damn those mages, can't kite to Dalaran...)
Learn crowd control. We've become the Volley Kings in Wrath, fixing a set point and just lobbing away at crowds of three or more, yawning and playing Kingdom Hearts in the background. Learn to draw one mob out of many, and capture it neatly, so that the rest goes down fast and the healer is not as in danger of getting one-shotted. You can learn both kiting/trapping and tossing a trap. You basically need to learn which mobs you can aggro away from the tank, as well as which traps to use, and how to stagger them. It is very useful when soloing, too.
It is all part of the talents that make up a Hunter, and to me, sets the hunters who've been playing from years, apart from those who've been playing for Wrath.
Good kiting is a real challenge. I've been practicing, but more often then not I'm FD'ing to drop the mob rather than actually killing it off. Sure, I could just sick my pet on him and gain some distance that way, but I feel like I should be able to do it with just traps and jumpshots. Not quite there yet.
This is pretty inspiring, though...
http://www.youtube.com/watch?v=Pw8Je6qqZ5s
I hope to be around when something like that happens.
Who am I kidding, I wouldn't mind being responsible for such chaos! 
Some Hunter specific addons I just can NOT play without anymore are:
Headshot - I really love using guns (esp as a dwarf) but I hate the sound. This addon replaces the default with a silenced gunshot.
"- 3 Silenced Gun Shot (M4A1 Carbine)
- 3 Unique Reload Sounds"
TB Anti-Daze - For when you forget you have Aspect of the Cheetah/Pack on. It turns off the aspect when you or someone in your group becomes dazed.
Track-o-Matique - Automagically switches your tracking to your current target's creature type and back to whatever you had before, after combat. For example I'm out mining so I have Find Minerals up but I aggro a Humanoid. When I target the Humanoid my tracking type changes to "Track Humanoid". After combat my tracking is reverted back to "Find Minerals"
Pfft, Koru, they had THREE people. Sheesh, I wanna solo a dragon. BAD. Maybe I'll attempt it this weekend with some of Tak's Soloing instances advice.
Cryp, welcome to the forums, and I can't live without my tracking addon either. I use a different one, but the same effect. It's also helped my dps a bit for those nights i'm still on Minerals when I should be on Marrowgar... *whistles innocently*
Hey, thanks for all the good advice. I'm had to take a small break but I'm back now lvling my hunter. I'll hopefully be in outlands by tonight. right now the only mods I use are:
Power Auras - So I always know when a sting isn't active on my target.
Pulse Cooldown - Whenever an ability comes off CD I get a it's icon flashed on the screen.
If you think of anything I may want to get please let me know. Thanks again.
I love hearing what other people use for addons.
The one add on that I CAN NOT live without is Quartz... make my life easier to make sure as many dots- marks- ect are up on the boss at the moment.
I also use:
Flo Aspect Bar- Just a UI cleaner. Make it so traps and aspects are on a small bar that an be placed anywhere on the screen.
cAspectOfTheViper- flashed my screen and a huge icon on my screen to say hey dummy your viper is still on.
Those are my hunter specific add ons.
I'll second the cast bar addon - whether it's Quartz or AzCastBar, either one is pretty useful.
OmiCC is one I've grown pretty attached to over the years.
NeedToKnow is pretty handy for DoT, cooldown, & buff timers.
This page has all of my addons listed, along with a brief description of each. You may want to give it a glimpse and see if anything strikes your fancy.