We have a timeshare on Maui and love visiting the Islands.
Last year was our first trip to the Big Island, and we stayed at the Hilton Waikoloa. While its definitely a great property, I think a key element is what exactly you are looking for in your vacation.
We found the HW to be sort of like an artificially created Hawaii within Hawaii, if that makes any sense. We felt sort of closed off from the island, as opposed to being a part of it. With the tram and all, I was feeling sort of like it was a
Disneyland type of artificially created environment. Obviously that can be a wonderful thing, but it didn't feel quite right in a hotel where the island itself is the attraction.
Then when we got home I read a review that said the same thing, so I guess I wasn't alone.
But like I said, I'm not really complaining about the HW. There's nothing wrong with it persay. It's just that like I said, I think it's important to think about what you want to get out of the trip. Do you want an all-inclusive resort where you could keep yourself occupied for days without ever leaving the property? Or do you want to do a lot of exploring, and be able to leave your room and walk right onto a beach like Waikiki or Ka'anapali?
As for websites, here's a few that might help:
http://www.gohawaii.com/
http://www.kauaivisitor.com/
http://w3.maui.net/
Also, as others have said, go ahead an ask questions either here or on the other forums. I'm sure you'll get lots of help.