Here is a fundamental WoW strategy guide.
Play your character rested whenever possible. Rested characters receive twice as many experience points (XP) from killing any mobs that you encounter. By building up a toon’s rested bonus to the maximum level over a few of days, you could potentially complete many quests and get the double XP bonus the whole time. So remember, the rested bonus is your friend. Why waste time if you don’t have to?
Green quests are your objective. They give the best bang for the buck and are easy to carry out. By doing quests above green you will discover that you will die several times in the process if you are mobbed by multiple monsters at a time. You’ll also wind up having to repair your gear more regularly, which is wasted time.
While leveling up, avoid instances. Running instances doesn’t get you the same amount of experience as just running quests. It is appealing for some of the items, but it’s slower.
Cluster quests together. Grab all the offered quests you can find when first arriving in a zone. Read through the quest details and try to cluster together as many quests that are in the same direction at once. Running back and forth between zones for quests is a nuisance and this approach will save you a lot a time and irritation.
Travel to other zones. If you have completed all the easier quests in your own race’s zones, do not be afraid to travel to another part of the continent or even to the other continent to aim at those easy green quests. You will find that the extra XP from completing so many quests quickly will turn you into a power leveler in no time.
The preceding WoW Leveling Guide has been used with permission from www.warcraftcodex.com