Expert Weapon Mastery- maxed asap. Spiracle use Arts - maxed asap. Spiracle Charge - keep at rappelz-item.com/tag/level/">level 1 till you get spiracle shock shot and freezing arrow, because you will be only using 1 spiracle skill.
Long bow training- max asap this skill increases your longbow dmg. Long Bow practice - max asap this skill increases your longbow atk speed. Marksmanship Practice- max asap this skill increases your range.
HP Increase- learnt till lvl 5 first adds 100hp per level we think. Wearing Archerers Suit - max as soon as you get it, because this will allow you to equip a hunter's suit. Defense Practice - We left this till much later, because as we said, you won't be tanking. Archerers Concentration - maxed asap, increases your accuracy.