You can give the option for TeamRaiser participants to registers their friends and family in one single registration process by enabling the Multiple Registrations option in your TeamRaiser.  This option is sometimes also referred to as Secondary Registrations.   To do this:
  1. Go to  Fundraising > TeamRaiser.
  2. Find the TeamRaiser you want to change and click the Edit link.  
  3. Go to 2.Select Fundraising Options and then look for the option labeled ' 5.  Multiple Registrations'.  
  4. Check the box ' Yes, allow a participant to register additional participants in one registration payment'.  Your constituents should now have the option to registers others with their registration.
If you do not see such an option, it may not be turned on for your site. Contact support to have this turned on.

Note that once the primary registrant has completed their registration, they will no longer be able to register any more secondary registrants. Secondary registrations can only be completed during the process of a primary registration.