Being new to PHP programming myself, the best place I had found to start (apart from here of course :-) was reading PHP Essentials. Cracking book that speaks to you in plain English and doesn't lose you on the way.
It's got the answers you're after, as, off hand I can't remember the whole syntax, but I think its' got something to do with assigning the contents of your message to a variable, then, defining who you want the message to go to and including your variable in the mail option.
For example:
<?php
$mailto="someone@somecompany.co.uk";
$subject="Testing";
$msg="Your message goes here";
$additional="From: \"Your Company\" <someone@somecompany.co.uk>\nContent-Type:text/plain\nOrganisation: Your Company";
//Do all your error checking here, for incorrect email addresses etc.
if($error==0) {
if (mail($mailto, $subject, $msg, $additional))
//add in your HTML 'thankyou' screen with PRINT/echo statements
exit();
}
else {
//error screen
}
?>
I'm sure this isn't the best example to get this going, but if you have named all your elements from your previous page, then, you shouldn't haven't any problem in referring to them in the following page.
i.e. <input type="text" name="message_field"> should be easy to access on the next page as $message_field. Or, as in the example above, just assign the contents of $message_field to $msg and include it in the body of your message like that.
If you still have problems, a cool example can be found at http://www.thickbook.com under the tutorial section.
Hope this helps