1) Hawaii has only one incorporated city: Honolulu.
2) The proper name of Honolulu: "The City & County of Honolulu"
3) The aforementioned "City & County of Honolulu" actually covers the entire island of Oahu, as well as all of the territory that belongs to Oahu.
4) What mainlanders think of Honolulu is actually "Urban Honolulu"
5) All of the rest of the "towns" in Hawaii are "CDP"s, or Census Designated Places. In fact, as far as the Census Department is concerned, only "Urban Honolulu" is "Honolulu".
6) If you have Vonage, calling Hawaii is free. Hawaii is over 3000 miles from where I am. Mexico City, by contrast, is just over 1100 miles from me, and it would cost me 6 cents a minute to call. It's cheaper for me to call an island I can only get to by FLIGHT 3000 miles away than it is to call a city I could concievably walk to (well, not that I would...walking that far would take me something like 10 years, and I don't really find that an attractive or enjoyable prospect, but I think you get the idea) that's 2000 miles CLOSER. I LOVE Vonage.
Yes, I called Honolulu. No, I didn't call Mexico City. I just picked a foreign country closer than HI that isn't Canada (because I can call Canada for free, too, and Puerto Rico.)
Also: The Leeward sides of the Hawaiian islands are drier than the Windward sides; the volcanic mountains that form the islands cause the currents to dump their rain on the windward side. Thus, most of the touristy stuff is on the leeward sides of the islands.
Everytime I spell Hawaii, I do so incorrectly. Well, in standard English (be that Commonwealth English or American English), it's OK. But Hawaiians spell it Hawai'i, where the ' is a glottal stop between the two i's. So why am not using Hawaiian English? I'm too lazy at the moment. Hawaiians: I apologize for being a lazy snot. Please don't flame me.
I learned more today, but at the moment, I think my head might pop from information overload if I try to explain it all. So I won't tell you about the forbidden island that is privately owned and not allowed to have visitors, or the hike up Wiliwilinui Ridge, or how the other side of the Koolau volcano fell into the ocean, and so the Koolau Range on Oahu is really just half of a volcano, or where the term "Shield Volcano" came from (but I will tell you that every volcano in Hawaii is one), or why it's nearly impossible to hike the entire length of the Koolau range, or the correct Hawaiian English ways to spell all of the above terms.
Go spend some time with Wikipedia. Between it and Google, you should be able to find everything I did, and even stuff I've forgotten how to express already.