There's no easy way to describe it (because each model requires slightly different instruction, improvisation, etc.) but if you want to get started some good places to start are ninjatoes' website [link] and nintendopapercraft dot com.
You can! Find a template for a model you'd like to build and just go for it! You might mess up but it's a learning process. In no time, you'll be making wonderful and detailed models of whatever you want!