Stat Priorities
Stat Ranking
For single target with appropriate traits:
Haste > Crit > Mastery = Versatility
Stat Outline
Haste: shortens the GCD and lowers the CD on rotational abilities such as Skullsplitter and Mortal Strike.
Crit: gives a chance for your attacks to do double damage and your Auto Attacks that crit give 30% more rage.
Mastery (Mastery: Deep Wounds): makes Deep Wounds do more damage.
Versatility: increases the damage you do and reduces the damage you take.
Stat Recommendations
Multi target situations tend to favor Mastery more, although it depends a lot on the situation.
The best way to calculate stat priorities for your character is to "sim" your character
Find out how to simRaces
All of the races are close in DPS so don’t worry about it, but Lightforged Draenei sims best, and Undead for Horde.
Enchants
Weapon
Gale-Force Striking is usually the best option for Arms.
If you are playing Arms for the big Bladestorm then I would recommend Deadly Navigation.
Rings
When it comes to ring enchants just go for what sims best for you, probably haste (Enchant Ring - Pact of Haste).
Gems
When it comes to gems just go for what sims best for you, probably haste (Quick Owlseye).
Consumables
Potion: Potion of Bursting Blood is best for single target, Battle Potion of Strength is best for cleave and AoE.
Flask: Flask of the Undertow.
Food: The best food is Swamp Fish’n Chips, but you can also use the buff from a Sanguinated Feast or Bountiful Captain's Feast.