Most of them are pretty good as they have every incentive to put you on fish. It's how they make their living, and people tend to want to use a charter again if they had a good time with that charter before.
Decide what specifies you want to fish and what season is open.
Find an appropriate charter who has an opening for the dates listed. He will probably know what species is biting best for the dates you'll be there.
Be on time and prepare for a 3 hr+ boat ride out to sea. I usually take a dramamine and try to sleep for the ride out.
Regardless of your success, TIP YOUR DECKHAND! Tips are the only way he makes his money in most cases. We usually try to tip at 20% of the cost of the charter.
Look into shore fishing as well. We usually go in April so I'm not familiar with the fall bite. But do some searching around and talk to some charter captains and they'll tell you what you can catch from shore. We've always had great luck catching black tip shark, sheeps head, pompano, and trout fishing off the beach south of Tampa (Anna Maria Island down to Sarasota). Sand fleas work great for shore fishing.