Also, I suggest subscribing to the Joomla Security Strike Team Alerts.
http://developer.joomla.org/security.html
Tips –
– Always back up your websites files and MySQL databases on a daily or every other day basis.
– Keep a full backup for at least a month (not on your web server, preferably on cdrom)
– Make note of all the extensions and plugins you have and check their websites periodically for any script updates.
– Check the Joomla website every other day for updates and security releases.
– Apply your updates to a test site first or make sure you have a backup before applying the updates.
Joomla is open source so you have to be on top of this stuff. Your clients may lose faith in you or your company when they see their site hacked.
Keep up with the latest and you’ll make a good impression!
😉