At right is The Magician from the Celtic Dragon Tarot. Except for the dragon spirit guides and the book open on her table, this Magician is par for the course.
This Magician's book makes me think of the Wiccan "Book of Shadows" which is a personal (for each witch) journal of belief, spells, magic, and the like. I love that this Magician has her book of spells at hand and I can't help but think of her as a witch in this deck.
Like other Magicians, the tools of her trade are around her. Her tools are also the suits of the Minor Arcana--a cup, a wand, a sword (in this instance, her sword takes the shape of an athame which has a handle shaped like the head of a dragon), and pentacles (in the form of accessories).
The candle can also be seen as a symbol of her energy, a sign that she works "in the light," or it may simply be viewed as a light source. Sometimes a banana is just a banana, after all.
In the positive, I see The Magician as someone who has great talent and skill. They have everything they need to accomplish whatever goal they set for themselves. The card represents creative power, manifestation, turning ideas into reality, greatness or the desire for greatness. This card could come up for anyone with a strong desire to manifest someone in their life or for someone with great potential to do so.
In the negative The Magician may represent someone who is wasting their talent or whose abilities are hidden or stifled. The lazy genius comes to mind with this card's darker side. I also think of greedy televangelists when I see this card negatively. Its dark side could certainly represent a trickster.
I associate the rune Dagaz with this card because so often The Magician is depicted with the symbol of infinity somewhere on the card. The symbol doesn't appear on this card, but that doesn't mean I won't think of it if I am working with this deck.