If you have a wireless broadband connection at home now you are pretty much good to go. All you need to do (if you haven't yet) is set up your PlayStation 3 to go online. This is done in the network settings found at the bottom of the Settings menu.
One thing i should mention is a number of people have had troubles with keeping a wireless connection going (mainly due to the wireless card in the PS3 lacking in quality somewhat). We recommend using a wired connection if possible.
Have a look at top of our forums and you'll find the PlayStation 3 guides section. In there you'll find a thread detailing setting up a wireless connection for the PlayStation 3. It should be of some help to set up the connection.