best php contact, mail form practice ?

hi all, could someone suggtest the best way to construct a php 'contact' form thats safe against spammers ?

I need the php to be on the same page as the form..is that a problem ? - how would I write that into the action ?

<form method="POST" action"***SELF ?***">

HTML:

need some advice !

Thanks.

 

use CAPTCHA CODE to get rid from spammers..

 

Easy way for you its recaptcha.net/plugins/php/