Since StarSan is an acid, you might not want to use it for the long term on the IC... I did it the first time I used mine, before hearing that you shouldn't...
I would just make sure it's clean before you put it into the pot. You can put it in pretty much any time from ~15 before the boil is done until flame-out... You'll want it exposed to the high temp wort for at least a minute, or so, in order to sanitize it. I think anything more than 1-2 minutes would be plenty of time to kill anything that's on the IC...