Some books describe The Magician as representing; will, mystery, organizational skill, creative talents, someone that can use the higher powers to materialize their desires. It may also represent someone with diversified knowledge that can be invaluable to a project you are working on.
But on the flip side (especially if the card appears upside down), it can mean deceit. You will usually have a gut feeling about this person but choose to ignore it.
In other words, this card is a warning to be cautious and keep your eyes open and also be aware of your own capability to deceive yourself and others.