Setting up Calendar and best practice sharing to coworkers

The solution we like to have in our shop is, each of the eight employees have there own dedicated calendar which can be viewed by other employees if needed and one of the employee has access to manage the calendars for scheduling.

I am pretty new with the OSX Server (5.0.15) and Calendar option, what are the steps to setup the calendar plus for each user?

Will I need to setup a account for each individual on the Macintosh where the Calendar is being hosted by OS X Server? I prefer not to have account on the hosted Macintosh where the users then can login.

Also will the employee have to option to few there Calendar from home or there iOS device?

At the moment we are sharing our one iCloud account to each employee that is assigned to a Calendar.

Also we have Mac Pro setup as a Xsan and another Mac Mini where the Wiki is setup and is active. Which would be the better solution to setup the calendar?

Thank you