To generate a PDF into PHP, there are two techniques: PDFLib or FPDF. PDFLib has some restrictions on licencing (commercial applications), I encourage to use FPDF because is free and Open Source, although PDFLib is rough and more complete (use your criterion). At
http://fpdf.org there are a place to download the class and good tutorials. Use $_GET or $_POST variables to get the form data depending the form method.
To send the email, mail() function or PHPMailer are commons methods to perform these assignments. Please take care to encode the attachment and the headers, set multipart content type first, then the proper content type and encoding in each part, we could send plain or html text and multiple attachments too.
In this example I've used FPDF and mail() techniques. I don't know if it is better move this code to snippets section.
<?php
// download fpdf class (http://fpdf.org)
require("fpdf153/fpdf.php");
// fpdf object
$pdf=new FPDF();
// generate a simple PDF (for more info, see http://fpdf.org/en/tutorial/)
$pdf->AddPage();
$pdf->SetFont("Arial","B",14);
$pdf->Cell(40,10, "this is a pdf example");
// email stuff
$to = "target@domain.com";
$from = "me@domain.com";
$subject = "send email with pdf attachment";
$message = "Please see the attachment.";
// a random hash will be necessary to send mixed content
$separator = md5(time());
// carriage return type (we use PHP end of line constant)
$eol = PHP_EOL;
// attachment name
$filename = "example.pdf";
// encode data (put attachment in proper format)
$pdfdoc = $pdf->Output("", "S");
$attachment = chunk_split(base64_encode($pdfdoc));
// main header (multipart mandatory)
$headers = "From: ".$from.$eol;
$headers .= "MIME-Version: 1.0".$eol;
$headers .= "Content-Type: multipart/mixed; boundary=\"".$separator."\"".$eol.$eol;
$headers .= "Content-Transfer-Encoding: 7bit".$eol;
$headers .= "This is a MIME encoded message.".$eol.$eol;
// message
$headers .= "--".$separator.$eol;
$headers .= "Content-Type: text/plain; charset=\"iso-8859-1\"".$eol;
$headers .= "Content-Transfer-Encoding: 7bit".$eol.$eol;
$headers .= $message.$eol.$eol;
// attachment
$headers .= "--".$separator.$eol;
$headers .= "Content-Type: application/octet-stream; name=\"".$filename."\"".$eol;
$headers .= "Content-Transfer-Encoding: base64".$eol;
$headers .= "Content-Disposition: attachment".$eol.$eol;
$headers .= $attachment.$eol.$eol;
$headers .= "--".$separator."--";
// send message
mail($to, $subject, "", $headers);
?>
Marked 
