Do you quarantine?

[amy]

Now that I have some livestock in my tank...not to mention the countless hours of work, I am beginning to worry about losing it all. lol
I have heard horror stories of adding a new fish only to lose everything.
So, what does everyone do?
Do you quarantine every new fish before adding it? What about coral and such? If so for how long? and whats the easiest method? 10-20 gallon tank?
Maybe I'm getting a little OCD and going over the deep end

Quarantine or toss em in? (after acclimating)

Thanks a bunch!