There are two different types of Quests in Imagica. There are On-Line Quests which you can find in the Teldar Library that is located in the Teldar City Hall. Those are always available and you can choose yourself whenever you wish to do one. Then there are Quest Master run Quests, those appear on a regular basis and of various formats. They are run by Imagica's Quest Masters, and you can find information about when the next quest will take place on the Quest Board in the Temple in Teldar.
Rules of Quests:
Quests have been created with great care. They are not made to kill you, but to give you something to do except beating endless mobs. To keep Quests alive, you may NEVER... and I mean NEVER... give hints to other players!
After Solving a Quest YOU MAY NEVER... give ANY information to ANY player about how to solve it. If you do give any information, you will be abandoned for any future Quests and all Quest-items gained will be taken from you.