How to connect? .. Wi-Fi?

I would like to be able to connect to the internet remotely on my laptop.
I currently use a Time Warner cable modem connection at home.
XP Pro.
4 yr. old laptop with unused card slot.

I expect to be traveling to major cities and staying at mid to large size hotels.

What do you recommend as far as which card to buy and how much $ should I expect?
Will I need to pay for a separate subscription?
Any tips on set up?