Quick Leveling Guide:

Level Guide:

Level 1 -9

Partying inst really necessary when leveling up in this stage, Take all available quest from all NPC's.

Press "M" or Map to see which NPC's have quest for you.

Quest Legend:

Gold - Main Quest - gives lot of EXP.

Blue  - Side Quest - gives a moderate EXP.

? - you have quest here.

! - you have finished a quest here.

Level 10-15:

Always take Adventurers Guild Quest for additional EXP and Gold. 
Tip:Selling Pouch is most of the times better than opening and selling it to the NPC's

Party Up for more EXP and do More Quest(More Party=Less ABP consumed).
Additional EXP gathered with party stacks up to 4 times(+1,+2,+4,+8).

Do solo and you end up emptying your ABP(Althea's Blessing Points) bar which means no Bonus EXP for you.

Level 16-23:

Dark Tower Dungeon Gives AVG 10%+ EXP(with ABP bar) per run and its also very easy to clear.

Recommended Party Size:3-4

ABYSS RUN

Add your Party As Friends for a little EXP BOOST.

Level 24 (MAX CAP for DNS SEA).

Dungeon Looting.

Minotaur Nest can be cleared 7 times.(Gives Epic Items).

BUNNY HUNTING!.