As I've said, you should go longer than a week.  You don't know when you'll get out there again, so you're going to want to see things.  If you're lucky enough to have a couple weeks, you can definitely fit in all the must sees without killing yourself.

Arrival day:
I won't count this as day one, because you won't get there any earlier than 5PM.  If you go in February, as I suggest, it'll be getting dark soon.  So don't kill yourself to get to your condo ASAP.  Just get your luggage and rental car, and take your time to find your way.  Settle into your place, and don't plan on much else.  If you aren't sound asleep two seconds after hitting the couch, you might think about going to Safeway or ABC for a few morning provisions (Coffee, Half & Half, Milk, Cereal, Bread, Eggs, Beer, etc.). 

PS - If you've found this page by googling an itinerary, you've probably skipped over one of the most important pages on this site.  Check out this page: Travel Arrangements.  Pay particular attention on where to stay.  It will make the rest of this itinerary more understandable. 

Day 1:
-AM Pool/Beach  
After flying for 15 hours, you'll need a day to relax and bask in the sun and realize why you came.  You'll probably be up at 3AM, because of the time change.  Aren't you glad you bought coffee last night?  Once the sun comes up, and you pick your jaw up off the floor when you see where you are, either find a lounge chair at the pool, or lay out your towel at the beach and listen to the ocean.  After a few hours, do the rest of your grocery shopping.  
-PM Pool/Beach  
Make a sandwich, and go back to the pool.  Relax.  After eating a lovely dinner on your Lanai, watching the whales jump in the ocean, take a walk down to the beach.   Now, settle in for the show you'll want to catch as many times as possible, sunset.  Don't forget your camera.

Day 2:
-AM Sunrise on Hale Akala       (<----more detail="" span="">
Use the time difference to your advantage since you'll be up.  Leave your condo around 3AM, and head to the summit.  Have breakfast at Kula Lodge on your way back down, after sunrise.  Go to either Makawao or Paia, walk around a bit.  Head home.
-PM Pool/Beach
(See day 1)

Day 3:
-AM Snorkeling
Take a ride down to Makena, and pick a spot to snorkel (Use your Maui Revealed book).  As I've stated previously, you'll want to do your ocean activities in the morning because the wind picks up in the afternoon, making it too choppy to enjoy. 
-PM Pool/Beach
(See day 1)

Day 4:
-AM West Maui Drive       (<----more detail)
Head toward Lahaina, or Wailuku, depending on which direction you'd like to do this.  Last year, we went the Wailuku way and found it very enjoyable.  It was a good call to do most of the stops for hiking, gawking and rock climbing earlier in the day.  That left a few hours in the afternoon to stop at Maui Brewing Co. for a beer, and walk around Lahaina for a bit.  Make some or all of the stops I told you about earlier, or add a few.  You've got all day, so take your time and take in as much as possible.

Day 5:
-AM Snorkeling/Pool/Beach
The choice is yours, depending on how worn out you are from the West Maui Drive.  Save some energy for the afternoon.
-PM Upcountry
If you didn't stop in Makawao after Hale Akala on day 2, do it now.  After, continue up to the winery and lavender farm.  You'll be taking a lot of pictures, the view is spectacular, especially if you're there late enough for sunset.

Day 6:
-AM Whalewatch/Helicopter       (<----more detail)
Choose between these two optional activities, which are really cool but not imperative with If you're too tired, just relax at the pool.
-PM Shops at Wailea/Wailea Sunset
Put on an Aloha shirt or a Sun Dress (depending on gender, or not) and take a beautiful walk along the path that runs between the beaches and hotels in Wailea for sunset.  Take your camera and take some great pictures you'll want to frame when you get home.  Before that, check out the high end shopping or maybe stroll the grounds of the Grand Wailea Hotel.

Day 7:
-AM Day Trip to Another Island
You could take a ferry to Lanai for golf, or to Molokai for exploring (Those are both on my to do list).  If you want to be really adventurous, take an early morning flight to Oahu.  This is not to be done without any plan.  You'll end up wasting a lot of time, and thinking you should've stayed on Maui.  Here's what I've done.  Have a car rented, and pick it up as soon as you land.  Have tickets for Pearl Harbor bought months in advance, so you can do the tour in the AM.  After that, you have two options.  1: Head to Dole Plantation, and circle the northern end of the island, stopping at the sites you want.  Head over the Pali Highway (stop at the lookout).  Save some time to go to Waikiki, and spend the balance of your time shopping, beach walking, eating, etc.  2: (my fav) Head directly to the Pali Hwy. (stop at the lookout), continue east and then circle the southern half of the island.  Pick your stops before you go, so you can budget your time.  Don't miss Makapu'u Lookout, Hanauma Bay and Diamond Head (you can hike to the top).  End your day at Waikiki, doing the afore mentioned.  Leave yourself enough time to drop off your car and check in for your return flight to Maui.  Hopefully, get the latest flight back.  It's a really ambitious plan, and only for the heartiest types.

Day 8:
-AM Snorkeling/Pool/Beach
-PM Pool/Beach (See Day 1)

Day 9:
-AM Whalewatch/Helicopter       (<----more detail)
You'd use this day for one of these activities (if you want to do the other one, or) if the weather didn't cooperate on day 6.  It might have been too windy.  It's also the reason we do this in the AM.
-PM Mama's Fish House
Get dressed up and have a fabulous dinner at Mama's Fish House.  Another photo op.  

Day 10:
-AM Snorkeling/Pool/Beach
-PM Pool/Beach (See Day 1)

 

Day 11:
-AM The Road to Hana       (<----more detail)
This is the only day of your vacation you might actually hope for rain.  If it does, the normally fantastic waterfalls along the route will be spectacular.  Plan on an entire day for this road trip.

Day 12:
-AM Snorkeling/Pool/Beach
-PM Lahaina Town/Luau
Take a ride over to Lahaina when you're ready, and walk around the shops, bars, marina and historic sites.  Have a light lunch if you haven't already.  Around 5, head over to The Feast at Lele for your Luau.  (Make your reservations at least a couple months in advance, they fill up fast.)

Update: The Feast at Lele is still good.  But, it has slipped in quality and

I would no longer put it ahead some of the others.

​

Day 13:

 

-AM

Pool

 

-PM

Begin packing.  Leave out your essentials.  

Head to the beach after dinner to enjoy your last sunset there.

Day 14:

-AM Snorkeling/Pool/Beach

Checkout is usually 11AM or noon.  After that, some places let you continue to use the pool and store your luggage in the office.  Some places have a hospitality suite for you to use before you head to the airport. If your place does not, you may want to consider getting a hotel room for your last day.   Your flight may not be until 10:30PM, and you may want to just relax at the pool and shower later instead of trying to kill time with all your luggage in tow.  When you do head for the airport (sniffle), stop at Walmart or Target and buy any last minute souvenirs for anyone you forgot.  Gas up the rental car and return it.  Check your bags after they get run through the agriculture screener.  Head to security.  Aloha for now (sniffle).