Ok, first of all there are five basic positions. These postions are simply first, second, third, fourth, and fifth.
To acheive these postions you must have something called turnout. Turnout is when you can keep your heel forward and your toes out to the side. For exaple, if you were standing facing something, you would have perfect turnout if the back of your heels were facing each other and your right toes were directly to the right of you, and same for the left ones.
Here is how you do the five positioins:
First: Stand with your heels touching eachother and your toes tuned out.
Second: Stand how you did in first poition, but with your feet about a foot apart.
Third: Stand with one foot how it would be in first position. Stand with the other foot directly in front of it touching it and have the heel of the foot in front be by the arch.
Fourth: Stand how you would in third, except move the foot in front so that the heel of it is touching the toes of the foot in the back. Now move the foot in front directly forward about 10 inches.
Fifth: Stand how you would in third, except move the foot in front so that the heel of it is touching the toes of the foot in the back.