FLL and MIA are 30 minutes apart. I let air fare be my determining factor. Yes, FLL is simpler and smaller, but if you can get a cheaper, direct flight into MIA could be worth the hassle.

I am more familiar with the Keys than the Glades. I enjoy Islamorada as a base, but I also like Marathon and Key Colony as alternatives. Islamorada has hotels from reasonable to exceptional. Restaurants from classic Keys casual to fine dining. From Islamorada you can fish, shop, kayak, or explore the middle keys from a central location. You are not far from Pennekamp if snorkeling is a possibility.

The Hampton Inn at Islamorada is a cut above your typical Hampton. They offer two BR suites, a very nice pool area and a mini-private beach. The Hampton is walking distance a couple of good restaurants. If you are looking upscale the Cheeca Lodge is a famous fine hotel. Favorite restaurants include Lazy Days and the Lorelei.

Have fun with this trip. Wish I were along.

Seconding what stumpworks says all the way through.

I spend about 6 months a year in Fort Lauderdale and am familiar with both airports. They are 26.2 miles apart so I would not consider driving somewhere from FLL to entail that much "extra" time.

I-95 in that area is a real "speedway" and that sometimes INCLUDES the local police and highway patrol so be aware.

I would base the flight on costs rather than into which airport.

Thanks! Where is a good place to base for a few days to explore the Everglades?

For the Everglades, I would suggest staying in Homestead. Here's a link the the NP visitor's center there:
http://www.nps.gov/ever/planyourvisit/coedirections.htm

You could stay on Miami Beach, but it's over an hour away and with Miami traffic, I wouldn't suggest it if you mainly want to explore the Everglades.

Also, your son may have fun doing the Jr. Ranger program there, both my sons did. They do an activity booklet, learn about the eco-system and wildlife, one ranger walk (I think) and they earn a plastic badge.

That time of year there are some excellent places for bird watching. Ask a park ranger and they'll tell you some of the best spots to see them.

If you go to shark valley, do the tram tour. You will see many alligators, especially out by the observation tower. We bike the loop, but I'm not sure if you would want to do that with a 7 yr. old, it's about 15 miles.

Enjoy!

Is Coral Gables a good place to stay while exploring Everglades National Park? Any recommendations for accommodations there?

Coral Gables and Cocoanut Grove are both nice areas to stay in. Coral Gables is +/- an hour from the Shark Valley visitors center in the Everglades.