You will see in in the "Monthly" display here, with a link (the +Google button at the lower RH corner)  to your root calendar where you can maintain it. For the site visitors-- both here and on the events list on the home page --  that button will add a copy of your event to the VIEWERS calendar.  Thus, visitors can't simply change your events from an embedded website. You can do it because you're logged into Google Calendar and therefor have write access, no matter if you're on the main Google Calendar page or a page with an embedded Google Calendar.

This "Admin"  page  will be password protected so only you will have access to this functionality.