coconuts play an important in southeast asisan cooking so i could give you a bit of insight...

if 1, get a copy of "How to Cook, book one" by Delia Smith from your local lib. as there is a detail description as how to do it.

2, if not possible, just punch a hole with the help of a hammer. lose the juice (not advised for cooking) through the whole. cut the coconut in half with the help of the hammer. Then use a veggie grater to shred the coconut flesh.

fresh coconut doesn't keep as long as the commercial one (for the obvious reason) and it's not sweetened. so if you are making a dessert dish, i think it's good to doubel check with the amount of sugar needed. i found some local ppl. here in malaysia add salt & sugar to "fresh" dessicated coconut in the cooking. but i haven't tried that myself so can't tell you the propotion.

hope the above helps