There are a couple types of wireless. I'm assuming you mean it connects to a wireless access point, before being routed to the Internet, as opposed to a cellular card. If it's a Linksys, that should be it. If it's a cellular card, it acts as a dial-up modem to your wireless carrier for Internet access.
To connect to a wireless access point, you first need a wireless access point. If you're using it at home, you'll need to purchase one, connect it to your Internet connection and configure it for connection and security.
If you mean you would like to connect via an access point you don't own, you'll need to find one that is open, unless you have mad hacking skills in which case I'll let you figure it out on your own. Many businesses like coffeeshops and restaraunts have open wireless access points for their customers. It will show up in your list of networks as Unsecured. Some hotels have wireless access points for their customers but change the password to connect each day. The front desk would have to give you the new password.