Whats the best way to get from the ft lauderdale airport to miami's port? (very budget conscious).

If you are getting your own flight how early should you have it arrive? for a 5 o'clock departure I'm arriving around 12 in ft lauderdale.

Try Super Shuttle (they have a website). Definitely cheaper than a taxi! I wouldn't pick a flight any later than what you have - that's cutting it a bit close as is, though you should still make it fine unless your flight is delayed more than an hour. For a 5 PM sailing you need to be on board no later than 4 PM, and earlier is definitely better. Cruise lines have security just like the airports, so you will have to allow some time for that at the pier as well.