It's a multi-level parkade, and very nice but a bit confusing to get around in. There are a couple of covered walkways to get to the terminal. It will be cheaper to do the Park n Fly but if you want snow-free the parkade is the way to go. You drive into the parkade and take a ticket. Before you leave the parkade on your way home put your ticket in one of many machines and it will tell you how much you owe. Pay with a debit or credit card and take your ticket back. When you drive out of the parkade you use your ticket one last time to raise the gate and exit. There is a cash option but that would take longer and I've never done it.
Alternatively if you have a Macpass to cross the Halifax bridges you can use that account to charge your credit card without needing to take a ticket. That's how we pay by the hour at the airport when we are meeting someone there.
http://www.hiaa.ca/default.asp?mn=70.1.235.242