block off a time on your calendar and click "Actions" and
then "New Meeting Request".  List the people you want the
invitation to go to with other pertinent information about
the meeting.  Send the email invitation.  When they
receive the invitation, it will have the options
for "Accept" or "Decline" buttons to respond.  They may
also add a message if desired.  You will receive a
response from these people indicating their availability.