@Lili Said
You'll definitely want to go up to Haleakala. I would recommend either at sunrise or sunset, that's when it's most beautiful. It looks like heaven, and I'm not exaggerating. But it WILL be cold, don't be like some of the naive tourists up there in an aloha shirt and shorts freezing their asses off.
The nicest beach on Maui, in my opinion, is in Napili, it's in West Maui. There are also nice beaches at Ka'anapali. But the water is clearer and smoother in napili.
Hana is massively overrated in my opinion. it takes forever to get there, it's a god-awful nausea inducing crawl of a drive that takes 5 hours...and when you get there...there's nothing there. Maybe a banana bread stand or something. Don't waste your time. I'm sure the white-people hating locals who tend to live back there won't mind you decided not to go anyway.
If you like hiking, you'll want to go to Iao Valley. There are also beautiful clear streams you can swim in. Don't go if you believe in ghosts though, a major war took place there, and there are a lot of rumors of haunting in there. So many people were killed there, the stream ran red with blood.
I guess it just depends on what you want to do there.
wow thats an amazing amount of information
thanks heaps