I love Miami! I go A LOT (ex wife lives in miami beach). Miami is all about food, drinks, and shopping.
Biggest thing you need to know? The south beach neon lights tourist strip area at night is REALLY FREAKING EXPENSIVE FOR ANYTHING. If you're hanging out on the strip and want a drink? Expect to pay $30+ for a jack and coke at some piece of shit bar.
I'll add to this, but must do things?
Lincoln Rd. outdoor mall. Do some shopping and check out the interesting stores. My favorite place to eat on that strip is Sushi Samba. Tuna Tataki, grilled sea bass, chilean corn are good choices.
http://lincolnroadmall.com/A chill lunch spot at the marina? Monty's. Also a cool little place to have a relaxed drink at night too without the south beach madness. It's a "locals" place.
http://www.montyssobe.com/Bayside marketplace yep go.
http://www.baysidemarketplace.com/Lapis Spa at Fontainebleau is a MUST do. You'll never want to leave the rain tunnel.
http://www.fontainebleau.com/web/spa/la ... r_journeysAlso while you're there it's probably my favorite day spot to hang out at. Rent a cabana by the pool.
http://www.fontainebleau.com/web/recrea ... anas_beachGo checkout the Wynwood Walls
http://thewynwoodwalls.com/Other good places to eat?
http://katsuyarestaurant.com/southbeach/http://www.runchickenrun.com/All add more....
Good places for a drink that isn't crazy?
http://www.normans.biz/Duffy's of North Miami Beach (people pull their boats up)
I don't know why, but this little hole in the wall spanish place makes a damn good breakfast:
Latin Cafe
7445 Collins Ave
Miami Beach, FL 33141
I'll add more
Want to dance the night away?
http://www.clubspace.com/ <--insane
http://www.livnightclub.com/I'll add more.
Oh, boat culture? Hm, I'll check out where you can rent one.