Secrets of Mage-y goodness

[Nightblade]

In my random fits of boredom I occasionally encounter, I began to think on just how certain classes are best played. Most of them are pretty simple, if you put your mind to it, and with time played comes experience and technique.

The only one, for some reason, that I can't seem to grasp quite off the start is the mage. What the devil makes them so hideously overpowered to begin with? Is it merely chain casting your pet into the fray? Or merely reclaiming at the end of the fight to cast a new one?

I'm half-heartedly thinking about leveling one just to pass time between the periods where I can interest my wife in duo'ing with me, and would appreciate a little insight onto some of the things to watch out for, or skills to try to master while playing up said pet class.

Advice, links to pages and strategies, and all the like are much appreciated.

Thanks in advance.