Help with installing the Mac plug in for the Blind Cafe website.

Hello everyone,
I just signed up for an account on the blind cafe website. I have never used one of these kind of websites before, so I have no experience to go on. I have my account all set up, and there is a link that says, Mac users click here to install the plug in. Being a new mac user I have no idea how to do this. Any help/instructions on how to do this, would be very much appreciated.
If anyone would like to contact me privately by email, my email is
[email protected] Thank you.