In iCal, you select on the left sidebar which calendars you want to be visible. You create a new calendar the way yoou describe it (File>New Calendar) and then in the left sidebar you make sure that this new calendar is the only one that has the checkbox checked. Then this calendar is the only one visible.
When you want to transfer this calendar to your friend, choose File> export calendar. This will create an .ics file which you can send to your friend by email, dropbox etc. Your frien then just dobbelclick on the .ics file, and the calendar will be saved in iCal.