Congratulations! You have a brand new baby Chromebook! You open it up, power it on, and... need to enter some WiFi information before you can start Chromebooking.
Below are the screens you should see, and the options you should select. Once done, your Chromebook should remember these settings but on occasion you may need to re-enter them.
Step 1: Select a network. From the initial "Network not available" screen, choose "Staff" from the drop down menu.
Step 2: Specify your Username and Password, and check the box to Save your Identity and Password. Here you'll need to fill in your Username (aka Identity) and Password. All of the other options should be set as shown below.