Welcome to LQ!
Since you will need to set up a network with windows clients you shall get familiar with Samba. Get familiar now with this tutorial
. Here you can control shares and their access rights.
Concerning file permissions these are basic *nix concept, all you need is to get familiar with unix/gnu principles. Here are few but good tutorials
you can download at your choice.
There are also documentations in your /usr/share/doc folders for particular topics. And about shell commands you have always "manual pages" just type in the terminal ~$ man <command here> and the pages will open.
Hope that helps.