By default, everyone's calendar events will show as "busy" rather than showing details. When you create an event, you can change the availability to public. When you do this, people will be able to see the details on your calendar for that one event.
You might want to share your calendar to your boss and coworkers so that they can see the details of your calendar. When you do this, they will only be able to see the event details of future events you create or past "created" events that you modify. This is a little undesirable, but it is how it works. Ideally you'd have to option of having past created events show details also.
But, if you share your calendar with someone and give them access to create and modify events, that person (your designate) will be able to see the details of past created and future created events.