Hi Sugarcubesea:
Everyone's posted a lot of good suggestions and places for Maui. We usually go to Oahu, but last year decided to try Maui for the first time.
We had a great time because a local friend who grew up on Maui and still has family there gave us her list with recommendations and some local places, if you and your family like or want to try local food.
Here's some information for the northern areas that she provided to us; but you may want to google or check yelp to make sure these places are still open, as a lot of local places are closing down. Plus it depends what time you arrive in Maui, if the stores are still open:
Stop at Costco, Kmart and/or Walmart to pick up things you'll need at the condo (if your car has room.) Stuff is expensive on Maui and for example soft drinks at Walmart are half the price you'll find in local markets. As you leave the airport and come to the first signal light (Haleakala Hwy.) turn left and Costco will be on your right. If you go straight (actually you veer a little left) at the first signal, Kmart will be at your left. I suggest stopping at Costco, then Wal-Mart as getting out of the Kmart parking lot may be difficult. Drinking water and a styrofoam ice chest are recommended if you are going to do a lot of sightseeing.
Going straight on the road (Dairy Road) past Kmart, you will see the Maui Marketplace shopping center on the left. There is a Sports Authority Store and other shops. Keep going down the road and you'll see Wal-Mart and Home Depot on your left. Continue down Dairy Road and you'll be on your way to West Maui.
If you want to stop in Kahului before heading to your hotel, there are three shopping centers.
Maui Mall has a local favorite ice cream (kind of like a ice cream and sherbet mixture) shop called Tasaka Guri-Guri Ice Cream, in the south side of the mall.
Near the airport is Da Kitchen Cafe, with large portions of food (chicken katsu is good) at reasonable prices, around $6~$12. 425 Koloa St., Closed Sunday, M-F 11-8, Sat 11-3. Also has a "Hole is the wall" location in Kihei.
There's also a Zippy's near airport. Zippy's are kind of like Denny's Diner, but has the good local Hawaiian stuff, plus the regular burgers or pancakes so a good choice for picky eaters in the group.
The Geste Shrimp Truck is parked on Kahului Beach Road next to the harbor. We heard is is listed as one of the 50 best food trucks in the nation but haven't tried it and hopefully as good as Giovanni's truck in Oahu.
Wailuku area:
Sam Sato's (1750 Wili Pa Loop, Wailuku) Breakfast & lunch only, Mon-Sat 7-2. Known by the locals for their dry min or saimin (noodles), pie crust manju and other local dishes like chicken katsu, fried rice.
Just past Sam Sato's is the Asian Star restaurant with good Vietnamese food.
Prices as usual are higher here than on mainland. What would be a $6 bowl of pho in Orange County is $10 here.
Archie's and Tokyo Tei are small Wailuku restaurants on Lower Main Street that serve Japanese and local food, nothing fancy, but good. Next to Archies is Tiffany's Bar & Grill, which friends like but we haven't tried.
For Poke and other local prepared foods visit Takamia Market, in the Happy Valley section of Wailuku. Ichiban Okazuya is another favorite local place.
Lahaina:
808 Grindz Cafe (7am-2 pm): Hole in the wall, mostly locals (at the time) great breakfasts for $5.75
Star Noodle (286 Kupuohi St) Upscale fusion place, now pretty crowded with tourists. Good ramen noodles, a bit pricey and long wait sometimes.
Honokowai, Kahana, Napili:
As you head north on the main highway past Black Rock, you'll pass the Royal Lahaina Resort. Turn left onto the Lower Honoapiilani Rd you'll soon come to a small shopping center on your right with a very large TImes Market. Past this shopping center on the right is a strip mall with Honokowai Okazuya and Deli, a hole in the wall with take out only, good food but prices have gone up.
L&L: Typical local plate lunch place with local favorites like chicken katsu, teriyaki, loco moco. Large portions, generally not too expensive.
Seahouse Restaurant (Napili Kai Beach Resort): Great view. Had portuguese sausage, eggs, fried rice. Tasted great and good for the arteries!
Kapalua Bay:
Sansei Restaurant: A bit pricey, but they sometimes have discounted prices during certain hours like 5:30-6 and 10:00. Get there early as the line gets long.
Sorry the info above was long, but I tried to cut out the other info to post her info for the airport/northern Maui areas.
Hope you and your family enjoy your time there!