To enroll TAs, instructors, guest, ect, to the course the user would first follow 
the same process as enrolling a student. How do I add a student? 
You may also need to create the role you wish to assign the user. How to create Custom Roles.

After you have enrolled the person and created the new role if nessecary, do the
following:

1. Click CUSR on the remote control.
2. At the Create User, Change User Privileges sreen, Type the username 
in the username text box or click the Select User link. The screen will then 
display the current class list. Select a username to modify the user privileges.
4. Click User Roles.
5. At the Change User Privileges screen for the selected user, scroll down to Add Roles.
6. Click the box next to the roles you wish to activate for the selected user.
7. Set the starting dates and ending dates for each role you selected.
8. Click Modify User.