Stat Priorities
Stat Ranking
Agility > Mastery >= Haste > Crit >= Vers
Stat Outline
Agility increases your attack power, which is just a raw damage increase.
Haste reduces the cooldowns of your abilities, the global cooldown, and increases your attack speed.
Critical Strike increases the chance for your attacks to do double damage.
Versatility increases all damage and healing you do and reduces the damage you take.
Mastery increases the damage of class abilities that deal Fire, Frost, or Nature damage and slightly increases the chance for Stormsurge procs. Note that as of 8.0 this is a whitelist, and items such as trinkets, or Engineering bombs are not affected by this anymore.
As always, the value of stats depends on your specific gear, and as such, you should use sims to find out which combination of your items is best.
Races
The differences between races are very minimal. Pick whichever one appeals to you. The only relevant racial is Stoneform, but if you need to ask if you need to roll dwarf, then you can make do without it.
Enchants
Cloak: Enchant Cloak - Chant Of Winged Grace
Chest: Enchant Chest - Crystalline Radiance
Bracers: Enchant Bracer - Chant Of Armored Avoidance
Boots: Enchant Boots - Defender's March
Legs: Stormbound Armor Kit
Rings: Enchant Ring - Radiant Mastery (Totemic) / Enchant Ring - Radiant Haste (Stormbringer)
Weapon: Enchant Weapon - Stonebound Artistry
Gems
Always socket a Culminating Blasphemite, a Quick Onyx, and a Masterful Emerald. Fill the rest of your slots with Quick Onyx for Totemic and Masterful Emerald for Stormbringer.
Consumables
Food: Feast Of The Divine Day
Flasks: Flask Of Alchemical Chaos
Potions: Tempered Potion
Health Potion: Invigorating Healing Potion
Weapon Oil: Windfury Weapon, Flametongue Weapon
Runes: Crystallized Augment Rune