I just started using Silverstripe. It is pretty cool. I want to start experimenting with the PHP and css and stuff, but not upload the changes to the website until I'm ready. What is the preferred way of doing this? It'd be kind of like a mirror website but with access to the same database.

So what do you all do? Copy everything to a second directory and open up a second web server through a different port or something?

Most of the time when I'm developing I will have a local development environment set up, depending on your set up this might be something like WAMP, MAMP or a virtual machine.

If you can get your local development environment as close to the settings on your live server that is a good thing so you won't end up with any unexpected problems due to php versions being different for example.

I have also been using a good tool called Vagrant recently which make the process of running a local virtual machine very tidy (though it has a bit of a learning curve to get up and running, well worth putting the time in IMHO).

Check out our installation documentation: http://beta.docs.silverstripe.org/en/getting_started/installation/

Hope that helps.