Wu Style Tai Ji Quan Form Site | A few basics to start with

start with feet one of your feet apart
put tongue on upper pallate behind front teeth, month closed (prevents biting your tongue, also connects energy channels)
relax hands, but full of energy (not completly limp) (helps for swimming in air -- if hands are stiff they will cut through, but if relaxed they can push the air) shake out hands and arms hard, then stop. should feel like this.
back stays upright throughout exercises. face faces whichever direction is front from the body, eyes follow hand motion
start facing north.
knees slightly bent. sink and rise up with breath
transfer weight. movement starts at the waist. pay attention to the hips.
for further explanation of tai chi principles refer to a classic text, or ask a more advanced student.

the beginning section