Securing debian stable

I'm running a small apache webserver off a debian stable machine at home: I'm planning on opening it up to the outside world on port 80, so I want to make sure I don't have any big security holes in the box before I do. The three main services I run off of it are apache, ssh, and postgres. I want to be able to access apache and ssh from outside my home network - just wondering, are there any good faq's out there for securing a debian system?