Subscribing to receive any alert is very easy and straightforward.  Simply log into your Client Console account with your Username and Password.  Once logged in, choose Account Settings from the left side of the screen.

Near the bottom of the page there are some checkboxes, to subscribe to a specific alert, you can simply check the appropriate options in order to opt in and then click Save.  To opt-out of any notifications just uncheck any boxes that are already selected and then click Save.

If boxes were checked, you will now start receiving the alerts.  If boxes were unchecked, you will be opted-out of receiving those alerts.