When playing a new character (level 1-10), leveling can be easier to accomplish by changing zones to another race's starting zone. Doing this after completing many quests in your race's zone and getting about to level 6-8, you can complete most of the other race's starting zone's quests fairly quickly, and pick up some nice XP and a little extra money.

        If you are a human, run to Stormwind and take the train (int he Dwarwen District) and go to Ironforge. Do the quests in that zone, and you can level up easy. Do this Vice Versa as a Dwarf or Gnome. This is a little harder as a Night Elf, since there is no train to get on or anything. First, get to Darnassas and go through the pink portal to get to the small village outside Darnassas. Either take the boat or take a grphyon to Darkshore. From here, run across the docks and take the other boat to Menethil Harbor. Then basically run to IF. Not very time effective for Night Elves however.