One thing I should note is that if you click and drag one of your special attacks down off the hot bar by accident then it is lost permanently, at least I haven't found a way to replace it.The best way to level up is killing things, doing quests does give xp but not as much as killing everything in sight does, and not as quickly.
Every odd level you get a passive skill, and every even one you get a active skill.
At level 11 you have the skills; there's swift strike (close combat), penetrating shot (bow), barbed arrow (bow), trap (out of combat), strong stance (out of combat), milestone ability (teleport), focus (gives full focus), fishing (hobby), Swift bow(bow), blindside(close combat), Scourging blow(close combat), Quick shot(bow), and set trap(out of combat). Remember to visit the trainer frequently, also check the passive abilities section, as I got the Crossbow ability which allows you to use crossbows which you cannot otherwise do as a hunter.
In the village of Michel Delving, next to the outfitter's with the dummies outside, there is a training hall. In here you will find the trainers for most classes, e.g. Hunter class
When you reach level 12 you get the tracking skill, this allows you to detect creatures around you, a menu pops up and there is a list of animals. You click on one and it appears on the minimap in the top right corner, at least there's a little symbol that appears in the minimap. there is also cry of the predator, which is combat skill which lowers a animal's morale and makes it run away for a bot and then it comes running back at you.
At level 14 you get the skill Find The Path, this you toggle on and off by right-clicking it. This skill makes you (and I think anyone else in you're fellowship) run faster.