[bitfolk] php hosting

So I've decideed to join the cool kids and try PHP - in particular, I've
installed roundcube.

Is there any good info out there on securing php? I'd quite like to not
get hacked, which seems to be a common problem with PHP web apps.

There's nothing all that good that shows up on a quick google - it
mostly seems focused at developers rather than running other people's
PHP code.

Michael