As Vijay stated, there's always the online manual, and you probably should read through it if you're very new to PHP (i.e. you don't know about variables, functions, classes, etc.).
However, if you just want to jump to what you need, I believe the following covers most of it.
http://www.php.net/reserved.variables
http://www.php.net/mail
http://www.php.net/file
However I don't grasp your meaning when you say "check the proper fill up", so you may need to do additional research to solve your problem.
Snib
<><