I use coconut quite often in my beers. Recently won a homebrew comp with a Hawaiian Porter that got scaled up to a 15bbl commercial system.
I basically do the following:
Toast the coconut at 375F for 15min, frequently stirring.
Add to secondary to taste. 2-3 days pale beer. 3-4 days brown beer, 3-7 days stout/porter
I usually add it to the keg so I can taste it daily, then transfer/remove when the coconut is at the level I prefer.