Belts are wrapped once around the waist to symbolize:
Pursue one goal.
Serve one master with unshakable loyalty.
Gain a victory in one blow.

How to tie your belt: Your belt should be tied in a square knot, right end over the left and under, then left over right and under. The ends should be even. If you're not sure how, respectfully ask an upper belt for help.

Here's how to tie your belt

Place the center of your belt across the middle of your back.	In front, cross the right end over the left.	Wrap the top end under and pull it through.
Pull it snug.	Check ends and make sure they are even.	Cross the left end over the right.
Wrap the top end under,	and pull it through.	Finished.

Meaning of the belt colors
The colors chosen are full of tradition. The colors of Black, Red and Blue denoted the various levels of hierarchy during the Koguryo and Silla Dynasties in ancient Korea. The main purpose of the belt in Taekwon-Do is to represent the philosophical significance of the Taekwon-Do practitioner.
White - Signifies innocence, as that of a beginning student with no previous knowledge of Taekwon-Do.
Yellow - Signifies the Earth from which a plant sprouts and takes root as the Taekwon-Do foundation is being laid.
Green - Signifies the plant's growth as the Taekwon-Do skill begins to develop.
Blue - Signifies the Heaven, towards which the plant matures into a towering tree as training in Taekwon-Do progresses.
Red - Signifies danger, cautioning the student to exercise control and warning the opponent to stay away.
Black - Opposite of white, therefore signifying the student's maturity and proficiency in Taekwon-Do. It also indicates the wearer's imperviousness to darkness and fear.

There are nine Degrees (Dans) of Black Belt