Use SCM with a PHP application like Wordpress

How do I use SCM with a PHP app such as Wordpress? I run my blog using Wordpress and all too recently became a big believer in SCM. I really want to put my site into subversion (that's what I'm using right now, maybe git will come later) but I can't think of the correct way to do it yet. Basically, my repository is set up currently with an 'implementation' directory and a 'resources' directory, with implementation holding what will eventually be published to the live site. I want to be able to preview my site locally without having to upload to the server for obvious reasons. However, to do this I found that I needed to actually install Wordpress locally (not just copy the remote site down to my local box). This was told to me over at Wordpress. This brings up the problem of being able to use SCM with the install because I need to upgrade my local site every now and then but this generates inconsistencies with subversion because it can’t track what’s goin...