I will be leaving my residence at the end of March.

Intent to vacate forms:
All the forms you could need and more - FREE
The actual form I need: Notice of Intent to Vacate
It was recommended that I send it certified mail and get a reciept: Acknowledgment of Notice of Intent to Vacate

Move In/Out Checklists:
One of four on Total Real Estate website

FYI: Why I'm Glad I had Renter's Insurance and My Landlord Should Be Too

Prepare to get your security deposit back (read and understand tenant rights in FL):
http://www.floridapirg.org/consumer/renters/rrpage4.htm
http://www.800helpfla.com/landlord_text.html
http://www.coj.net/Departments/Community+Services/Consumer+Affairs/Floridas+landlord+tenant+rights.htm