Mage career quests are all the first step in receiving them from the trainer in the mage area of your race's main city.

Each stage has its own career quests even if the previous ones aren't done or finished, as long as the level is reached you can receive them. The Great Water quest after level 50 and the Auror Mage's Recipe (which can be exchanged for a level 58 blue trinket) are quests that come out of the Doom. The water quest can be directly to find the Doom Library NPC received, the library in the Doom West, from the north into the words of relatively close, less than 5 people can easily complete. The Orphan's Cookbook is a quest book from the Doom Boss, and can also be bought at the AH, and the quests triggered by the book are also turned in at the library.

Basically, they are all junk quests, harder to do, time consuming, but you don't get any good quest rewards, so it's recommended not to do them. The only 2 quests that are worth doing are the water and piggybacking quests.

Preliminary you do not waste time, do other common tasks, occasionally with people team brush copy enough, mage early do not need too good equipment.