Hunting Boards
Hunting Boards can be found in: Comodo, Geffen, Hugel, Juno, Lighthalzen, Payon, Prontera, and Umbala. They should show up as a + on your minimap.
For killing 150 of a monster, you gain extra experience equal to 112.5 kills (75%) of that monster. There are a lot of monsters available, and you can accept all quests at once, and turn them all in at once. [1]