Night Elf Leveling Guide

1. Pick up the first quest, The Balance of the Nature from the NPC in front of you and kill 7 Young Nightsabers and 4 Young Thistle Boars. Turn in the quest. Congratulations, you are level 2 now.

2. Pick up the following quests: The Balance of Nature and [class]Sigil

3. Walk to your class trainer and hand in the quest.

4. Go to location 1. and kill 7 Mangy Nightsabers and 7 Thistle Boars. Hand in the quest. You must be level 3 now.

5. Pick up these quest from various NPCs around Aldrassil (the huge tree): The Woodland Protector, Webwood Venom, A Good Friend

6. Go to location 2. and hand in the quest at Iverron. Get the folow up: A Friend in Need

7. Start killing the spiders near the cave until you get 10 Webwood Venom Sacks.

8. Go back to Aldrassil and hand in: Webwood Venom, Woodland Protector and A Friend in Need. You are level 4 now.

9. Get the follow ups: Woodland Protector, Iverron's Antidote and Webwood Egg.

10. Move to location 3. and start killing Grells and Grelkins. Get 8 Fell Moss and 7 Hyancinth Mushrooms. Keep killing them until you get level 5.

11. From location 4. get 4 Moonpetal Lillys and then go back to the cave near location 2.

12. Go into the cave and while you kill the spiders go to the end of the cave and you find Webwood Egg. Kill spiders to get Webwood Ichor.

13. Go back to Aldrassil, hand in the quests and pick up the following ones: Iverron's Antidote and Tenaron's Summon. Don't forget, that Iverron's Antidote has a 5 minute timer.

14. Go into the top of Aldrassil and hand in the quest Tenaron's Summon and get the follow up, Crown of the Earth.

15. Go to Iverron and finish the quest.

16. Go to location 5. and while standing in the water fill the vial. Then go back to Aldrassil and hand in the quest, pick up the follow up. By now, you should get level 6, if not, kill some more mobs.

1. Take the road leading south of Shadowglen and just before you leave Shadowglen get the quest Dolanaar Delivery from the NPC, keep folowing the road. You will see another NPC, pick up the quest Zenn's Bidding from him. Follow the road until you reach Dolanaar, hand in the quest Dolanaar Delivery and Crown of the Earth.

2. Get these quests in Dolanaar: Denalan's Earth, A Troubling Breeze, The Emerald Dreamcatcher and the Tiwsted Hatred.

3. Go to location 6. and kill Nightsabers, Webwood Lurkers and Strigid Owls. Find the Moonwell and use your jade vial.

4. Go to Starbreeze Village at location 7. and kill all Gnarlpines and then go to the top of the inn. Talk to the lying NPC: finish the quest A Troubling Breeze and get the follow up, Gnarlpine Corruption.

5. Go outside the inn, go into the small house and from the closet get the Emerald Dreamcatcher.

6. Keep killing Nightsabers, Webwod Lurkers and Strigid Owls util you have 3 Strigid owl Feathers, 3 Nightsaber Fangs, 3 Webwood Spider Silks and 7 Spider Legs. Go back to Zenn and finish the quest. You should be level 7 by now.

7. Go back to Dolanaar and hand in all your quests and get all the follow ups: The Relics of Wakening, Ferocitas the Dreameater and Seek Redemption!

8. Start looking for Fel Cones, they can be found near the location 8. While doing these go to location 9. and finish Denalan's Earth. Pick up the new quests: Timberling Seeds and Timberling Sprouts.

9. Start killing Timberlings around you and get Sprouts. Finish the quests at Denalan. Now, you must be level 8.

10. Go to location 10. Kill Gnarlpine Mystics and the boss. Loot his necklace.

11. If you found all the 3 Fel Cones go back to Zenn and hand in the quest.

12. Go back to Dolanaar and hand in the quests.

13. Move out of the town and follow the road to the west. While you follow the road you must meet a patrol giving you the quest The Road to Darnassus.

14. Go to location 11. and kill Gnarlpine Ambushers. you will need to kill 6 of them.

15. Caution! You may need a group for this quest. Go to location 12. and go into the den. Kill the mobs inside and get all the 4 items required for the quest Relics of Wakening. Speak with the druid inside and get the quest, The Sleeping Druid.

16. Get the Shaman Vodoo Charm, which drops from Gnarlpine Shamans. When you got it go back to the druid, hand in the quest and pick up the follow up. You are surely level 9 now.

17. Go to location 12. and kill the Rageclaw then go back to the druid and turn in the quest. Go back to Dolanaar and finish all your quests.

1. Follow the road out of Dolanaar to the west. until you reach Darnassus. Finish all your quests and get the follow up: Tumors. And get the quest: Tears of the Moon.

2. Go to location 13. get the quest Enchanted Glade and kill the harpies until you get all the required quest items. Go back to the quest giver and hand in the quest.

3. Pick up the follow up: Teldrassil. And go to location 14. and kill elementals until you get 5 Mossy Tumors.

4. Go to location 15. and kill Lady Sathrah and loot her Silvery Spinnerets.

5. Go back to Darnassus and finish all your quests.

6. Congratulations you are level 10 now. (If not just kill some more mobs) Now you may finish the remaining quest in the area or you can move to the new zone Darkshore.

If you want to get level 80 under 8 days, I recommend you to check out the in-game iDemise Leveling Guide, which is the best guide available as it tells you exactly what to do and puts an arrow in the middle of your screen pointing in the right direction. You will never get lost again!
It is an universal guide, so it covers all races and classes not only night elves.
Actually, it is an automated in-game guide, so you don't have to alt+tab out the game to check out what the guide says. It automatically chooses the best quests for your level and will give you advanced tips to further accelerate your leveling speed.
Virtually, you will follow the fastest route to level 80!

I recommended iDemise Guide to one of my friend and he got his level 80 druid in 8 days. He was a complete newbie with no gaming experience. Read his story here.