joomla module development with form - how to proce

I'm creating a simple Joomla 2.5 module that will have an html form.

mod_mymodule/tmpl/default.php:

<form method="post" id="myemailform" action="">
    <label for="ReferralName">Enter Name:</label><input type="text" name="name" value="<?php echo modCamcloudReferralHelper::getReferralName(); ?>">
    <label for="ReferralEmail">Enter Email Address:</label><input type="text" name="email">
    <label for="ReferralMessage">Enter Message (optional):</label><textarea class="message"></textarea>
    <span class="countdown"></span>
    <button type="submit" value="Send Email">Send Email</button>
    <?php echo JHtml::_('form.token'); ?>   
</form>

I have a helper class at:

mod_mymodule/helper.php - this just has some utility functions in it.

My question is what is the usual convention here to process my form on the server side. I tried to find examples of what people have done but I can't seem to find anything. Do I just put everything in the helper class:

<form method="post" id="myemailform" action="..\helper.php">

Or something like that? Thanks in advance.

Yes, you should do form processing in module helper class. Keep any logic out of the template file, and you can use mod_mymodule.php to call helper methods and assign variables before including the view file.

Do not set as form action helper file! I think in your case action should be the same page, so you can also ommit action url.

Edit: As requested in the comments, this would be the content of your mod_mymodule.php

// include helper file
require_once dirname(__FILE__).'/helper.php';
// call some method of the helper class
$items = modMymoduleHelper::getItems();

$moduleclass_sfx = htmlspecialchars($params->get('moduleclass_sfx'));
// render view file from mod_mymodule/tmpl/default.php, $items is available in the view file
require JModuleHelper::getLayoutPath('mod_mymodule', $params->get('layout', 'default'));