Paladins are different from other classes in that they own various leveling builds. Each of that functions independently and interchangeably. The decisive factor of how much they affect lies in your ability.
If you want to gain XP, you can grind, quest, PvP, and play dungeons, or use any collaboration of the above. Retribution will help you fight your way smoothly, and Holy and Protection do you good in dungeons.
To make yourself level as a pure care bear Holy Pally, you will find Quest and Grind disappoint you. But you can do dungeons and group PvP. That will make you a star in all groups.
Holy Paladin Leveling
Damage output is not what Holy Paladins are good at. But you can do well in protecting their partners. It is dull for you to quest because you cannot move fast until when your member is a Warrior. To level up quickly, you can do more dungeons or battlegrounds queues, making sure your group members are alive.
Protection Paladin Leveling
This build aims to achieve the integration of AoE tanking capabilities and stacking damage buffs. The ultimate destination is to gradually diminish surrounding monsters. Protection talent tree offers many items, like Blessing of Sanctuary, Holy Shield, Retribution Aura, and Consecration. We can advantage from them great amount of AoE capabilities. The unison of the above matters would beat groups of 5, 10, and even 20+.
Retribution Paladin Leveling
Contrary to Protection, Retribution Paladins are better for questing. You are good at individual fighting, whereas Protection can handle ten mobs that you have no desire for. And you also benefit from your heavy armor, heal and Word of Glory.
Different builds require different fighting skills. Gear is the fundamental factor of victory. The better gear you have for your Paladin, the better result you will achieve in WoW, PvP. You can see more information on Paladin gear by visiting /wow/pvp/paladin.htm