Laptop and travel question?

I’m traveling around the world for over a year and heres my plan. Buy a laptop with a Wi Fi card and Download Skyppe to use as an internet phone in Wi Fi zones. I’m going to bring one of those Golden Lantern key chain thingees to tell me when I’m in a Wi Fi zone. I’ll also be using the laptop for E-mail, checking bank accounts, plane/hotel reservations, ect. But I’ve never used Wi Fi before.
1. Is Wi Fi secure? Could people read my passwords? I’ve heard the horror stories of internet cafes and thought doing it on my own would be safer.
2. I’ve got AOL, but would I need it? Or just Internet Explorer?
3. Is it free once I’m in a Wifi zone?
4. Is there anything else I’m missing? Thanks!