Hotels:
West of the airport in Doral (large golf resort) there are many hotels to choose from. The intercontinental west miami is a good choice.
Just south of the airport is an area called "Blue Lagoon" and the Sofitel or Hampton Inn are good choices.
Both of these areas are on the side of town that makes it easy to head west on US41 on Friday morning.

Food:
Lots of choices, I tend to recommend Cuban cuisine when people ask about where to eat in S. Florida.
Versialles is a sit down place that has a lot of history.
http://www.yelp.com/biz/versailles-restaurant-miami
La Carretta is another that I always visit when in Miami. There are multiple locations and there is one on Calle Ocho (SW8th St./US 41) South of the airport and one near International Mall West of the Airport.
http://lacarreta.com/
Both have good traditional Cuban food at a fair price.

When you leave Friday morning you will head to US 41 westbound towards Naples and once you get past the suburbs (west of the Florida Turnpike Extension) you should reach Shark valley in around 45 minutes. On the way to Shark Valley you will pass the Miccosukee Casino and a few airboat tour operators.
Shark valley is great...you can rent bikes to ride the loop to and from the obeservation tower or you can take the tour tram. both are fun options.
http://www.sharkvalleytramtours.com/
From shark valley it will be another hour to Marco.

This should be a good start....