These steps would be similar for all versions of Chrome, though names of buttons and options can change a bit depending on the particular version of Chrome.
Click the "Customize and control Google Chrome" button on the toolbar and then select Settings.
Scroll down the list until you see the "Show advanced settings..." link and then click on it.
Scroll further down the list until you see the Network settings, and then click the "Change proxy settings..." button.
On the Internet Properties window, click on the "LAN settings" button.
In the LAN Settings, uncheck the box that says "Automatically detect settings." And then, in the Proxy Server section, click the checkbox to enable "Use a proxy server for your LAN...".
In the Address field, enter the IP Address of your Proxy Server, and the Proxy Server Port Number in the Port field. You will receive the IP Address and Port Number of your Proxy Server(s) in a separate email.
Press the OK button and then press OK again to save your settings.
Now when you surf the web, you will be surfing by using the Proxy Server. The first time you open a webpage, depending on your account's authentication settings, you may be asked to enter your credentials, which were supplied in your Welcome Email.
To stop using the Proxy Server, repeat the above steps, but uncheck "Use a proxy server for your LAN..." and recheck "Automatically detect settings" in the LAN Settings.