Resto shamans in pvp have no real cookie cutter gemming, or spec, or gear build. Everything is based on your comp, how good your allies are at peeling and how good you are at staying alive.
Shamans do rely on resilience and stamina more than the other healers, so the resilience pvp trinket is a must. Also, for almost all comps you are going to use the SP Battlemaster's trinket or Corroded Skeleton Key as shamans lack the "oh sh1t" button and this serves as a weak one.
For gemming and spec, it's personally preference. There are 2 'main' spec themes though.
A spec devoted to LHW and one to HW.
For LHW you would pick up all the talents devoted to LHW and free up talents that help out HW. You gear towards crit more-so than mana/5.
For HW you would pick up all the talents devoted to HW and free up talents that help out LHW. You gear towards mana/5 more than crit.
The HW spec is probably the most popular among better shamans, but success is still seen in LHW. I've found LHW specs to work better with more aggressive players and it is the spec I personally prefer, getting your mana regen from crits from LHW proccing water shield.
LHW - Base Spec -
http://www.wowhead.com/talent#hZMhMhoZVceucosxkbIRt -- You can put the points from Tidal Focus into Tidal Mastery due to preference and you still have 8 talent points to spend.
HW - Base Spec -
http://www.wowhead.com/talent#hZMhMhoZxcfuIcsxkbIRt -- You still have 6 points to spend
Based on playstyle you can grab reduction on grounding totem/Nature's Guardian/Extra Int/Extra Crit
As for the spec itself, there really isn't a cookie cutter for what you need to have, and there is yet another 'preference' thing in Nature's Guardian. Some shamans don't spec into it at all, some go as deep as 4 points into it.
Shamans -should- gem for at least 6% hit and ~135 or less Spell Pen. This again is based on your playstyle and comp and if you are comfortable having things missed or resisted in combat (This also is more important if you play with no real dispel -ie RLS)
I personally love that there is no 1 -best- spec, regardless of what people tell you. Shamans do well with both specs in the same comps just based on what they are comfortable doing and I love that. Try them both out, see what flows better. Goodluck!