Well WoW will becoming in my mail In a few days.
1Q.I have play this before on a friends account and I learned that you had to play your class correctly if you want a raid group to let you in. So I have my eyes set on a elemental shaman, but I don't know what my second spec that I would get at lvl 30.

2Q. One other question which of the three talents which is the fastest for leveling.


3Q.The last question: which is the most successful in pvp and or pve

I don't really understand your 1st question, but I guess you are referring to Dual Talent Specialization. I would choose Resto as either your Main Spec or Off Spec, because it is very handy in Raids and Dungeons.

2nd Q: Enhancement shaman is the easiest for leveling, but once you are high enough (Level 75), you should switch to Elemantal, because that's the level when you'll be able to learn Lava Burst, one of the most powerful Shaman abilities.

3rd Q: All 3 classes have their pro's and con's in both PvE and PvP. Resto is a healing class, and increases your importance in raids, the other two specs are DPS specs.

Personal experience: A year ago, when I was still playing WoW, I was a Main Specced Resto Shaman with an Enhancement Offspec. I used to be Elemantal, but all you do is spam: Flame Shock, Lightening Bolt and Lava burst, and it gets very boring after a while. Enhancement on the other hand has a very interesting DPS rotation.

Either way, play what spec you like best and is the most fun. Have fun and play with moderation