So you want to start playing Arena/PvP as a Resto Shaman.
At first you have to cover the Basics
Gear, Stats, Skilltree.
I wont cover the possibilty of a second Specc as eleor enhancement yet, i will mainly focus on a healing spec.
Here this is my Shaman Another, as u can see im playing on a German Server, EU-Proudmoore. Realmpool: Blutdurst.
Must have Stats for PvP
Hitrating
Hit 4%, u can go for more, bt as far as my experience goes u should be just doing fine with 4% hitu will need hit as u want to shock or hex ur enemies in PvP. U can get hit however u want, im rolling with hit ring and amulet.
More Hit? A Caster should definitly have around 6% hit because of some Racials:
4% Hit + 2% on Bloodelves
+ 2% Draenei/Undead on Shadowspells
+ 2% Gnome on Arcanespells
+ 2% Dwarfs on Frostspells
+ 2% Tauren/Nightelves auf Naturespells
Spellpenetration
Hands Down 130 Spellpen or more, Shocks and hexes can be and will be game winners, u dont want ur enemies to Resist ur spells.