clintharris.net has published a very detailed article that teaches you how to host your Self-signed Certification for free.

If you manage your own web server and want to secure your website with SSL encryption (i.e., use “https://� URLs) you must obtain and install an X.509 certificate. Buying a certificate can be expensive, though, often costing upwards of US$100 per year. The cheapest option is to create your own, “self-signed� certificate for free. There’s a popular misconception that self-signed certificates aren’t as secure and that you must accept browser security warnings to use them; this is false. If securely distributed and installed in a browser, a self-signed certificate is just as secure as those sold by Certificate Authorities such as Verisign and will not cause browsers to display security warnings. This document attempts to briefly explain what certificates are, how to create a self-signed certificate that a browser can safely trust (i.e., no browser warnings), and how to use it without being vulnerable to man-in-the-middle attacks.
Click here to see the whole text.