Personally I have found the simplest setup to be using the RoboRIO setup to provide DHCP (which I think it is the default setting) and then making sure that your wireless connection on your laptop is configured to use DHCP as well.
The roboRIO webdashboard (accessible through the USB connection) will show you this:
http://s3.amazonaws.com/screensteps_...2FL2Yl%2Bns%3D
The laptop wireless config should look like this:
The most important part is that they match... either both set for DHCP or both set for a fixed IP address.