User group and file writing problems - help

I have 512 linode on ubuntu 10.04 LT running LAMP, created sites are per tutorials provided.

I have created a sudo user "nuser" to handle file upload etc as per linode guide (http://library.linode.com/securing-your-server) but when my php script try to write files it says permission denied (755 is the permission and owner is nuser).

So i have installed FAST-CGI and mpm itk (as per http://library.linode.com/web-servers/a … 0.04-lucid">http://library.linode.com/web-servers/apache/php-cgi/ubuntu-10.04-lucid)

But what group to assign in "AssignUserId webeditor webgroup"? So that my nuser is able to write files. (If I assign root in webgroup it works fine but assigning root is safe?)

I dont know how to add a group which is able to work in this scenario for writing files.