I think it depends on what you want to do while you are there, how much you want to spend, and what kind of place you want to stay in. If you don't care, and all you want is a flight, don't go through a travel agent.
yeah, and hit up the library...i'm sure they have a ton of books on hawaii if you're looking for the places to see, the restaurants to eat in, etc.
If you are going to Maui, I can ask my husband for ideas...he went there, and did a lot of cool stuff while he was there.