A note about associating users with groups -- on some systems, you'll find that every new login account is associated with an identically-named (and usually identically-numbered) group. On other systems, all login accounts will belong to a single users group. The approach that you use on the system(s) you administrate is up to you. Creating matching groups for each user has the advantage of allowing users to more easily control access to their own files by placing trusted friends in their personal group.