Most monitor arms are fairly simple to set up and install, but make sure that you check the instructions that come with them for peace of mind that you're doing it correctly. In most cases, monitor arms attach to the back of your monitor using a VESA mount, which is a square arrangement of four screw holes, and then the base clamp is attached to the back of your desk.
Different arms have different bases and mechanisms for attaching to your desk (or a wall), but in most cases, the options we've chosen will all attach to your desk using a clamp system that doesn't require any work on the desk itself. It's important that your desk is strong enough to support the weight of your monitor arm, and display, and that it won't topple backwards.