Level 1~40: Ape Mountain
Level 40~70: Bird Island ( could start from level 1 alternatively)
Don't Forget level 15, 40, 70 promotions at job center.
Start getting good gear:
Level 70 Unique Boots or better
Level 67 Elite Coat +2 or better
Level 70 Elite Bow +2 or better
Level 70 Unique Ring +1 or better
Level 67 Unique Necklace +2 or better
Level 62 Elite Hat +2 or better
Level 70~73: At Advanced Zone At Alien Apes by scattering them.
Level 73~108: Lab 1 and get Speedarrows
Now you should be wearing
Elite Boots +1
Elite Armor +3 or Super
Elite Bow 1 Soc Or Super With a RDG
Elite Ring +2
Elite Necky +3
Elite Ears +3
Get a Praying Stone (M) And get everyday 2X exp from PrayingStone before you enter lab2.
Level 108~115: Lab 2 enter with ears and scatter magic monsters.
Need more levels
Level 115~120: Lab 4
Easy VP guide here:

As for myself i got level 110 in 2 weeks with full elite +3 and Super Heavy Ring +3 starting from level 40 as i reborned all my stuff with a friend of mine.