I spent an afternoon there a few weeks ago whilst transitting from Minneapolis to Orlando. Spent the whole time on the top deck (only two levels) of the parking garage immediately in front of the terminal. Good for viewing, but not superb for photos, but there are some opportunities.
I contacted airport Public Relations before getting there and they advised me to tell the airport police what I would be doing before commencing, and they were extremely friendly - allowed us just to get on with it without any bother.
I have some shots from the visit on my web site (URL in my profile ?).