Enjoy:
http://technet.microsoft.com/en-us/library/bb332063.aspxThe above link takes you to a "on-ramp" page. You don't need to read every single link (unless you want to). I would suggest going through the first few links to get an idea of how it all works. Then, depending on the type of certificate you have deployed, choose the link that applies to your particular situation.
There are quite a few components that you need to address to make autodisover work:
SSL certificate, DNS records, as well as the Autodiscover service itself.