Kahuku Point is at the very top of the island; it takes about 45 minutes to an hour to get there from Kailua. There's just the one road that goes around, you see, and it hugs the coastline - it's one lane - so it's not always a quick trip although it's not really far.
Kahuku is pretty nice. They grow sweet corn and papayas and shrimps there, and lots of other things. There used to be a big sugar mill there; they finally demolished the remains of it this year. It's rural and quiet and people are pretty cool there.
Kahuku is like 'the country' on this island and whenever we have visitors, we drive around the top of the island because it's really pretty and you get interesting views when you're up where the pineapple fields are, and also it's not too far to the surfing spots at Sunset or Pipeline. And a restaurant called 'Breakers' in Haleiwa that I like, especially in the winter when the surfers are in town for the big waves off sunset.

If you look on the right side of the map, there is a peninsula labeled Kaneohe Bay Marine Corps Station. Near that are two dots marked "Kailua" and "Lanikai". I live basically between those dots. Follow 83 around the island.
See the NW edge and how it's dotted? No road there. If you park and hike into Kaena point it's a good place to see dolphins.
You should check it out. The winter brings big waves and rain to the windward side of the island but the temperatures are still high 70s and 80s. If you have a place to stay, I totally recommend spending a week or two hiking and snorkeling and doing things in the relaxed way that just lets you be. No tour buses, no forced marches. I know this great hike back into the mountains that ends in a rock canyon pool and waterfall. You can dive off the cliffs on three sides into the really cold water. It takes a little while to get back there but it's totally worth it.