I'm comfused with how roles work.
Is there any difference in assigning the role at user level, ie in the profile to assigning it at system level? When would you assign a role at user level?
Ed
IMHO you would very rarely indeed assign a role at user level -the main instance that comes to my mind is if you have a parent role and you assign that parent to the user their child -then they can follow their child's profile around and see what grades/blogs etc they have been doing. Or could be a tutor/mentor. (Mind you - you would very rarely assign a role at system level either!)
Just following Mary to say that most roles are assigned in a course. If you assign roles at the system level, those people will appear in every course. You rarely want that. What you usually want is a teacher in a course and some students for the teacher to teach. You rarely want all students in all courses.
Probably, you want to be investigating the flat file method of uploading users, which you can find in the documentation on this site.