The previous reply is basically right. Since I'm not sure quite what you're looking for, I'll give a little more with some explanation.
Anti-clockwise refers to the direction of travel around the room, if the dance you're doing does travel. To go clockwise is to go head-on into oncoming traffic -- bad idea.
Swing in the center is an extreme of the fast dancers on the outside, slow dancers on the inside rule. If you're not travelling, like for swing which generally stays in place, then you should be as close to the center of the floor as possible to allow others to easily travel around you. Slow travelling couples stay near the center to allow faster moving couples to get around them along the outside edges of the floor. It's rather similar to driving.
I think those are two of the most important points to remember. But also do your best to avoid collisions and both people in the couple should be watching for them. Bumps will happen though and when they do, apologize regardless of who bumped whom. And don't try to teach if you weren't asked for help, it's not a classroom and teaching should be left to the dance teachers anyway.
A few other points: always be polite, try not to turn down requests to dance, avoid monopolizing partners, and try to smile, be positive, and have fun. :) I can list some more things that I've picked up on and gathered, but I'm not sure if they're quite what you're looking for. I can give you more info and/or some URLs if you want, just ask. I hope this helps.
