A carefree youth strolls down a mountainside holding a white flower, accompanied by a white dog, and about to step off a cliff.
The beginning of all things, living in a state of pure, childlike (but not childish) innocence.
What it Means to Me
The fact that The Fool is card number zero speaks to it's symbolism. This is what exists before all else, and without which all else is meaningless. The arrival of the Innocent into the world is what triggers all of the events that are about to transpire. Being a card without a real number also implies a spiritual element to this card as the zero is outside of the world of real numbers, but our number system depends on the zero to function, so too is The Fool outside the world of human experience, but without it the physical experience could not exist.
The Fool comes from the mountain top, implying heaven. He is childlike, but not childish. He is pure. He is open. He is free. He will have challenges (as the cliff before him attests) but he will approach them with a pure heart (symbolized by the white flower) and will have assistance in avoiding or overcoming them (as the white dog beside him promises).
Place in my Journey
The logical place for this card is at the beginning. This is a state that we all share. What happens next is what makes us different.