Guildmaster Quest, or "Minor Quests"
Class: Any
Level: Any?
Prerequisites: None
Sacrifice: None
Rewards: Experience Bonus, Legend Mark
1) Go to any guildmaster, and ask him about a quest.
2) Select to find out about a new quest.  He'll tell you a short story about why he wants you to kill a particular creature, and you'll get a legend mark "On a quest to kill the (whichever creature)".
3) Kill the aforementioned critter.
4) Return to the guild and say "complete" to end the quest.  The legend mark will change to "Completed 1 minor quest" (or add one to that number, if you've already completed one quest).