How do I set an "Owner" for my contacts?

See also Auto filter of contacts by user

To create an Owner field (to select the person who is responsible for managing this contact) go to Admin System on the menu.

Open custom fields for the module where you want to add the field (An Administrator user can access from the Admin section - click on your name to expand the menu).

Give the field a name (example Owner)

Add a helpful hint so that other users will know how to use the field (this will display).

If you want the contact list to automatically display only contact where the user is set as owner select the check box Is AutoFilter? (Please note that these users will still be able to access other contacts by clearing the filter, however otherwise even when using the search field only their contacts will be displayed.

Select the field type from the list Client user - This will display the users you have in your system. New users will automatically be added to the drop down selection. 

Click on Save Custom Field. 

Please note that you can edit the field name and the hint but once selected it is not possible to change the field type.