When you first connect to the TEW-655BR3G/A you are greeted by a setup wizard that walks you through most of the items you need to get up and going. Of course, you could also skip this and move right to the advanced setup, but for many the wizard will be a great place to start.
The wizard takes you through everything, except setting the admin password. Unfortunately you still have to log in to get that changed.
Just six steps and you can be up and running (ok, more like 12, but still not bad).
You can choose the WAN type here and also change it in the advanced settings.
Wireless Encryption setup is part of the wizard, making sure that at least your WiFi network is protected.
Just confirm the information, click finish and then head into the advanced settings to change the default admin password and configure the 3G modem you are using.