Linux user administartion, permissions, 100 Most Popular photoshop tutorials

100 Most Popular photoshop tutorials of 2008
http://www.photoshoplady.com/the-100-most-popular-photoshop-tutorials-2008/

linux: Managing accounts and groups
http://www.redhat.com/docs/manuals/linux/RHL-8.0-Manual/admin-primer/ch-acctsgrps.html

linux: Setting User Permissions
http://www.webmasterworld.com/forum40/1555.htm

good: Setting Up File Permissions on Unix
http://www.onlamp.com/pub/a/apache/2004/05/28/apacheckbk.html

good: Linux Permissions
http://www.zzee.com/solutions/linux-permissions.shtml