Hosting more than one website on a single distro/server is quite common, and "good practice" is only limited to how you configure it.
To host a second website on the same server, simply add another virtual host to your server config. You can find the guide for your distro here:
http://library.linode.com/lamp-guides (if you installed Apache)
http://library.linode.com/lemp-guides (if you installed nginx)
If you're hosting an HTTPS site, however, the best practice is to host it on an isolated server (no other websites, applications or data other than what needs to be processed/stored by the SSL site), especially if you're dealing with highly sensitive information.