How to Raise a Holy Paladin
Before we begin I want you to know that raising a holy paladin means that you wont be able to solo very well. That means if there is a quest that requires you to kill a boss , chances are that you will be defeated unless you are in a group thats helping you , this also means if you barge in to a group of monsters , chances are very low that you will emerge victorious. But negatives aside , at higher levels (40+) you will be invited to group quests and raids because of your healing ability's. Like that old BG (Battle Ground) saying
"Never try to kill a paladin , their health is too much and you will never get them close to death , even if you do , they'll just use bubble or their friend will arrive"
On to the tip.
Quest Method
Do every quest possible , I mean if you see an "!" on your map , charge to it like a wild beast , this is the fastest way to get to level 40.
Grinding Method
A little slower method but it helps you explore and see new places , now if your using a hammer , fight monsters about 2 levels lower than you , if using a mace fight monsters 1 level below. Learn to use more weapons at Iron Forge or Stormwind City. If using a 2 hand sword , fight monsters 1 or 2 (sometimes 3) level higher than you. Best weapon for grinding , make sure you have the weapon that suits your level.
Ive noticed that every 2 levels you get new skills to learn at the Paladin Trainer. So make sure , if you can , to check out the Paladin Trainers.
Have fun with your Holy Paladin.