Lots of good ideas in here. I'm writing this from Honolulu as I type. I go to Oahu every two years for two weeks since I've been like 5...

Things I can bet you'll manage to do whether or not you read this:

• Eat Spam
• Eat a lot of rice
• Shop at an ABC store (think 7/11 that's for tourists and locals alike) and also on EVERY street corner of EVERY island)
• Notice how clean the air is. Even in the worst parts of Honolulu, it still smells better than New York
• Notice how FAST the clouds move. There's no mountains to stop them, so their movement is visible just by looking at them.

Okay, Oahu/Honolulu stuff... yeah. I may be 21, but I don't drink. Sorry there. There's probably plenty of places on Waikiki beach though (Big tourist spot). Surfing is really easy to learn here, as the water is warm (I'd say 60 - 70F), there's rarely any coral, and during the winter you have the North Shore kick up. That being said: DO NOT LEARN TO SURF ON NORTH SHORE OR WAIKIKI BEACH. North Shore is mainly for expert surfers in my opinion (This is where they get the famous footage of 10 foot piplines), and Waikiki beach is for the newer surfers, mainly tourists. Many rent fiberglass surfboards, and you may very well get cut up by them running you over. I can try to dig up this one surf company that I went with once, they have a nice hidden beach (its public though somehow) that no one seems to know about, if you want.

Next up, tourist attractions which even though you'll eventually become a local should probably still see:

• Diamond Head National Park (Aka Oahu Volcano, its about 5? Miles from Manoa)
• Pearl Harbor / USS Arizona Memorial (Do I need say more?)
• Hanauma Bay (spelling?) (I think someone already recommended this, but do what they said and go early in the morning- its gorgeous)
• Luau
• Farmer's Markets. I've found some awesome stuff at them.
• Try a spam and pineapple burger, you can basically get pineapple, coconut, and Macadamia nut everything here
• If you like Pineapple, the Dole Plantation. You will be sick of pinapple. Try the Pineapple Dole Whip if you go.
• During the Winter, whales appear at Honolulu (I think) aquarium. Might be worth it.
• See North Shore, if you don't actually surf it. The waves are pretty cool.

Some are repeats of others, but I thought I'd back up their opinions.

If you're up for island hopping (not too expensive for a day last time I did that- to be fair that was a few years ago...), I know Hawai'i (as in the big island, not the state) has some more active volcanos as of late. Additionally, there's this one forest near Kona if I remember correctly. Theres a big waterfall, and the trees grow like 200 feet tall. They do not however, breath fire.

Additionally, I'd recommend at SOME point going to Kauai. Its really beautiful. The only things I can recommend to do there other than observe are go to Ono Burger (Literally a secluded burger shack) and maybe go zip lining with this one tour company. They have a really big zip line. Oh. Also, everything on Kauai is on stilts 'cuz of the constant flooding. Well, most everything. Its pretty cool.

I don't know if you cook, but food IS more expensive in Hawaii, especially Oahu, especially Honolulu. That being said, some things are way easier to find here (mainly fish surprise surprise). Unlike most mainland stores, you'll be able to find sashimi grade ahi just sitting in the market. I bought some yesterday actually. I did however pay $25/lb... but the color and taste was amazing. Yeah, I get it that I can't present, but it was GOOD, and that's still about 1/2 the price I'd be paying in a mainland store for a pound (usually I think you get 4-6 oz for 17 - 22 USD in the mainland.

I'm gunna edit this as I think of other things I enjoy/enjoyed doing in Hawaii.