See New Features Rolling Out Soon
Go to groups.google.com
Click the Create Group button
Give your group a name like "mysharinggroup"
Set Select Group type to "Email list"
Set Group visibility to "All members of the group"
Get the group's email address. It will be like "mysharinggroup@googlegroups.com
Choose who can see your site
On a computer, open a site in new Google Sites.
At the top, click Share .
Next to "Published," click Change. Then choose the option "Specific people".
Enter the email address of the Google Group you want to add, click Editor or Published viewer.
Click Save or Done.
Visit your Group
Click Manage members
On the left, select Invite members or Direct add members
Visit your group
Click Manage members
Click the box next to a member
Click Actions and select Remove from group
Visit the group and click NEW TOPIC in order to send messages to the group members.