Are you aksing about PHP as a shell script language? If so.... yes, PHP can be used as a shell scripting language on Win32 (Unix too🙂 As to where you'd look for information... the only article I'm aware off which deals with PHP Shell Scripting is:
http://www.phpbuilder.com/columns/darrell20000319.php3
I think your best bet is just to hack up some scripts which automate whatever it is you want to automate on your system and go from there. Just remember that many of the system variables you're used to using in a web environment won't exist since those variables are generated by the httpd server and accessed by PHP.
If you're not asking about PHP as a shell scripter, could you rephrase the question to be a bit more specific to the info you want?
--geoff