Well, first stay away from Key West unless you are ex military and can stay at Boca Chica. Prices are at least $4.00/ft.
Other than that sage advice, my experience in Florida is limited to anchorages:
Sarasota has a very nice anchorage right near the heart of town. Dinghy to the beach and walk to town. They have many street fairs and festivals scheduled in the winter.
For a couple of laid back places try Boca Grande and Cayo Costa State Park. In Boca Grande you anchor with your stern tied to the shore mangroves. Easy walk to an upscale town. Cao Costa is undeveloped and feels remote, but it really isn't.
I can't help you in the keys other than the Key West observation. Once you get to Miami, No Name Harbor on the southern end of Key Biscanyne is a real delight. It is a bit of a hoot on weekends when the Cuban Navy takes over, but during the week it is very pleasant.
And of course no cruiser should miss Vero Beach. Nice moorings and first class facilities.
This past winter was unusually cold and you didn't see too many days wiith highs over 80 in Jan and Feb. Who knows what it will be like next year.
A few "don't miss" places are:
1. Sarasota – the City Marina (Marina Jack's) is located on the downtown waterfront. Shops and good restaurants abound. The Ringling Museum is a short cab ride away, as is St. Armand's Circle.
2. Boca Grande – Take a slip in a marina or anchor in the basin, with your stern to the mangroves. Great town for a stroll. Good restaurants. See how the rich folk live on their winter "break". A friend of mine put it well when he said "All the damn rich people are running us millionaires out of town"! Pres Bush (Sr.) used to spend the week between Christmas and New Year at the old Gasparilla Inn. Always a side-show when that circus comes to town.
3. Pelican Bay, at Cayo Costa. Just south of Boca Grande Pass. Beautiful anchorage, beautiful beach, short dinghy ride to Cabbage Key.
4. South Seas Plantation on Captiva Island. With all the money you have saved by anchoring out you should be able to afford a night or two there. This is a world-class resort. Don't even think about a holiday weekend – $5/ft-3 night minimum. They closed for two years after hurricane Charlie and spent $140M renovating.
5. The Keys are full of places to anchor or you can join in with the crowd at Marathon and pick up a mooring in Boot Key Harbor. There are slips to be had and last year the marinas were far from full because of the economy. We spent about $900/month for our 36' boat.
The left coast of Florida is a great cruising location.
Don't miss the Dry Tortugas/Fort Jefferson. You'll need a good weather window but it's well worth doing.
If you are going to spend any time in Fort Lauderdale consider staying at Marina Bay. The facilities are great and a good jumping off place for road trips. You will have to rent a car or use taxi's but at that time of year you will save more than enough on dockage to make up for it.
Right now we are at the Municipal Marina in St. Pete – great place to visit and you can walk to everything. Farmers' Market on Saturdays.
Coming down the coast, Everglades City is a nice stop, the historic Rod and Reel Club has cheap dockage.
Anchoring off Cape Sable beach is nice too, in good weather.
Key West is a tourist trap in my opinion… you can anchor in New Found harbor (good over night spot). there are also good spots north of Bahia Honda, off little pine key. Bahia honda (anchor bet. the bridges) is a good stop for the day, i woudnt' spend the night there.
Going up the coast, if you stay outside around islamorada, you can grab a mooring at Indian Key. After that, i like the inside route better. Plantation Yacht HArbor is one of the best marina in the mid/upper keys, Have not been there in a couple of years but reasonable and very nice (Park, pool, etc…)
I like anchoring north of Pigeon Key/ tavernier, very remote, makes you feel like you are miles away "from it all". good water.
After that, a stop at Eliott Key in Biscayne Bay is a must… nice clear water. Boca Chita is nice too, on week days, channel has a 6' MLW at the east end so you shuld be fine.
No Name Harbor is good on a week days, on week ends it's too crazy, we dont' go there anymore. too many loud obnoxious idiots… but you can land a dink and walk to the village (groceries, drug store, etc…)
A better anchorage is on the west side of KB, between the sandbar at the SW corner and KBYC. good protection, calm. you can land a dinghy just north of KBYC behind the presbypterian church/school and walk to stores. I've done that a few times, nobody said anything
Otherwise not a lot dinghy landing in Miami beside Dinner Key. By october, the mooring field should be operating (yeah…right…) but it's up to 40' anyway. smart,isnt' it? you can land a dinghy there and walk to the grove. good location for reprovision.. restaurants, etc…
Further north, thru jupiter it's all $3 a ft marina… there is anchorage on the north side of Lake Worth. In St Lucie, i like the anchorage in Hooker Cove, jsut off the ICW but the channel has shoaled up and I haven't tried it lately (the boat i captain draws 6+). 5' should be fine.
I like stopping at Cocoa Beach, tehre is a marina just north of the bridge which is reasonable and near the town, with some nice restaurants and shops.
Further north, anchoring near New SMyrna is limited with larger boats…. Daytona Beach doens't appeal to me much… St Augustine Municipal is in a great spot, near the old town, but $3 a ft. there is room to anchor.
Not much north of St Aug until Fernandina Beach, a very nice little town.
Hope this helps… obviously www.cruisersnet.net and www.activecaptain.com will be your most visited sites for the next few months… as well as http://www.atlanticcruisingclub.com/search/MapNew.aspx which i like when looking for marinas.
Just a couple more thoughts.
1. Sarasota is installing a mooring field so the anchorage that David mentioned will likely be gone by the time you get there. I was in the dockmaster's office last month and they had notices posted warning the anchored boats there when and where the mooring field construction would begin.
2. Key West has another marina at Garrison Bight. Since it is not anywhere near the hullabaloo of Duval Street, it is preferable to many folks. You do have to be sure that you can clear the power cable at the entrance. It is charted at 50' but I'd sure call and have a conversation with them about that!
Also, there is a mooring field on the E side of Fleming Key, near Garrison Channel. Not ideal in northerly winds but OK for the prevailing SE.
3. What lots of folks do when they want to see Key West is take the shuttle bus from Marathon. It costs just a couple of bucks and you don't need to worry about parking, DUI's , etc. Way cheaper than renting a car.