Help with groups, please.

[Steve Simons]

I want to give full access to /var/www/* to members of the group 'authors'.  I 
created the group with 'groupadd authors', added steve to the group with 
'gpasswd -a steve authors' and changed the group of the files with 'chgrp 
authors /var/www/*'.  After logging out and in as steve, why do I get 
permission denied errors?