Hi Riaan,
As for implementing the HTTPS/SSL layer, that's done within the web server software, and (virtually) transparent to the underlying CGI application (in this case, PHP, which then runs Joomla).
Start with entering the address to your site, but prefix it with https:// instead of http://
That will tell your browser to try and access the site using an encrypted connection, and if your server has been set up properly, you should see your website just as usual.
If you don't see your webpage, or get various warnings, then the server is not properly setup to handle HTTPS for your domain, and you'll probably have to get in touch with your service provider.
Once your server is setup properly and certificates are in order, the next step would be to head for the menu manager in Joomla. You should edit any and all links heading to your Form(s), and make sure you set the "SSL Enabled" System Parameters is set to yes. This will ensure that these menu-links will always start with https:// regardless how the user entered the webpage.
As an extra "safety", you could add something like this at the top of your form html code:
<?
$application =& JFactory::getApplication();
$url =& JFactory::getURL();
if ($url->getScheme() != "https") {
$url->setScheme('https');
$application->redirect($url->toString());
}
?>
That should force the browser to redirect to the secure form, should the user try to access the unsecure one.
/Fredrik