When I sailed out of Tampa last year, they were nearing completion on the construction of a brand new parking garage right across from the terminal. I imagine its open by now. We had to park in a lot a few blocks away and then Carnival provided free shuttles from the parking lot to the terminal. Best I remember, parking was $10 per day then.
Maybe somebody else has cruised more recently and can give you more details. You may also find the information you need at the port website. I think it's http://www.tampaport.com/cruise.htm
Will sail on Victory in 10 hours and 10 minutes. Yayyy!