How to Pug.

Be a good pugger. There are a couple things that are very important to do when you are pugging. I shall list them nicely for you.

1. Don't be a ninja: Being a ninja gets you blacklisted. Also if you ninja before the last boss, you may get kicked from the party and you'll have to wait the queue again.
2. Don't get in front of the tank: Stay behind the tank at all times. If you get in front of the tank, you are liable to pull something. The tank may not care to save your ass.
3. Don't be an ass: Be polite, say hello, maybe talk during the instance- if you have time. Eg. In Culling of Stratholme, make fun of Arthas, you have the time and the motivation. A bad place to type lots of things would be Black Morass, Violet Hold or the first bit of Halls of Reflection.
4. Know the instances: Know where you are. Know how to get to where you are. Know where you want to go. Know where the bosses are. Know the boss fights. A big help for this is the Atlas addon. It includes maps of all the instances, along with boss locations.
5. Know thy GYs: Know where the graveyard is and how to get back into the instance if/when you wipe.
6. Know how to play: Try to figure out your best rotation/priority system. You can visit elitestjerks or some other theory crafting site, or you can figure it out yourself. Look at your talents and see what improves if you do something else before it- think for yourself.
7. Let people be aware of your intentions: If you have a time limit, certain quests you want to get done, or an achievement to do, let people know before you start. This way, if they will not let you/cannot help you, you will not have to explode when bad things happen.
8. Give (and recieve) tips: If someone is standing in the Whirlwind, or standing in the fire let them know, kindly. If someone tells you that you are standing in fire, or that you are not standing in the sparklies (which can be good, on occasion) thank them, and adjust your strategy.
9. Watch the mana bars: Especially if you're the tank, make sure people have enough mana to keep on goin. If you're in a group with 2 rogues, a warrior, a DK and a priest, well the heals still has mana- make sure they have enough before CHAERGEING in.
10. Thank them: Even if your granny and your 2 year old cousin could do better than the healer and the tank, thank them for getting you through the instance.

Amazingly enough, it came out to be exactly ten. When I first 'finished' the list, I had 6 then I added more because, well, they're important.