User groups are defined in the User and group security project under the Resources node in Solution Explorer. 

• To manage user groups, double-click the User and group security node (or alternatively, right-click and select Edit users/groups from the context menu). The User/Group Editor will open in the editor area, with the group information showing on the left box and the user information showing on the right table.
  

• The Administrators group is a predefined group that comes with the Resources project. To add a new group, enter a new group name in the text box at the upper left corner of the editor and click on New Group. The new group will appear on the left column.
• To add a new user to the list, enter the user name in the text box at the upper right corner of the editor and click on New User. The new user will appear on the list, where you can enter the desired password. Upon saving the editor, (CTRL-S or cmd-s) a Uid will be assigned to the new users.
• To add a user to a group, select the desired group name and then check the box next to the user name.
• All changes in this editor must be saved using File>Save or the shortcuts CTRL-S (cmd-s).

For more information about setting security properties for a solution, visit the chapter on Managing Security Settings.