If you really want to get a lot of information about the whispers, go to Lostpedia and look up the whisper transcripts. Basically all the whispers can be decoded and people have established what is being said. I enjoy this sort of thing - they aren't massive spoilers as they're all fairly jumbled and random but it's amusing to know what is being said.

Be warned, though: Lostpedia is full of spoilers and other such things.