HTTPS Everywhere: Deep Dive Into Making the Switch

Not only are some browsers now throwing flares when forms are presented without encryption, but Google is starting to notice as well.
Bottom line - it's time to get a cert and make your site work over encrypted connections.

Here's a detailed article that will take you through the steps required to get HTTPS working on your site(s).

https://www.lullabot.com/articles/https-everywhere-deep-dive-into-making-the-switch