samba - Dec 2008 - setup shares-priveledges-groups for 2 groups of students

Running a Ubuntu 8.04 server with Samba 3.0.28a + IceWM + WebMin +  
Thunar

Samba is up and running

Confused about setting up the actual share space and rights for  
yearbook students and video students

I see something like this at root:
a shares folder    /shares     and inside it 2 folders      ---  
yearbook      and   video
students in the 2 groups will each have individual logins and home  
directories - all of the yearbook students will also have read/write  
access to the yearbook share but cannot access or browse the video share
I am working from the CL so Linux commands to setup these shares  
would be great -- I also have Webmin up and running



Last would be the share setup in the smb.conf file.  Any examples  
would be very helpful




Your local public school geek thanks you !!  I've been doing some  
reading - but some examples would be of great help!