To protect against firesheep style attacks and general privacy leaks, it is recommended to host your site using TLS (HTTPS).
If you do setup TLS, it is important to test your site with ssllabs.com/ssltest/ to ensure that it is setup properly, as it is easy to accidentally misconfigure TLS. (Test OK)
If you enable TLS, you may also want to configure your webserver to send the strict-transport-security header. This will improve the security of your website against eavesdroppers quite a bit, but at the drawback that it means you cannot decide to stop using TLS for a set period of time.