Yes one of the most frequently asked questions deserves a whole post about it! Before you go through these, please ask yourself the following questions:
1. Do you enjoy attacking safely from far without going near your enemies, devasting them with a deadly blast or multiple hits? Or do you seek the thrill of rushing up to your opponents and making them tremble, in the face of the grim reaper?
2. Do you like a short, swift, explosive battle, or a long battle of attrition to be the last survivor?
All these is because your skills will be fixed once you level up to level 25. No more reset(for now) and the only way to get more skill points besides grinding your levels (crazy slow) is the check out the mal-wart (black market) for bread. Bread gives you 3 skill points each, and are sold at 3 for 50 gold. You can also get more bread from Treasure-hunting (Lv 25 Golder Bay) which gives you a chance to get 1 bread. Default is 4 skill slots, but VIP5 or 30day login bonus will unlock it too. Thus, skills with an either or "/" can both be chosen with 5 slots.
A range attacker relies almost purely on mana. Of course when you run out of mana or encounter mana-sapping idiots (Evil Prince pet), you will still end up dealing physical attacks!
Archer: Corrode(0CD)/Weaken(0CD)/Devourer(CD4), Explode(CD4), Snapshot(CD4), Revive(P)
Mage: Firing(CD1), Lightning(CD5), Ice Armor(CD6), Revive(P), Snapshot(CD4) (Only if you equip xbow)
A warrior does not need active skills. It would be nice if they have, but with such a low mp, running out of mp to cast is most likely to happen in one or two rounds. Below I have a few styles for you.
Thick Troll Warrior: Revive, Double strike, Blade, Revenge/Bomb/Fatality
The Passive-Aggressive Man: Revive, Counterstrike(CD2), Double strike, Revenge/Blade
The Angry Hulk: Bash(CD1), Counterstrike(CD2), Revive, Double Strike/Revenge/Bomb