if you haven't then i would suggest you do. hit
www.povray.org and download it its very powerful and simple to use, when your in ac3d and have a model you want to render, position the camera correctly in the 3d window and hit the render button at the top of the page!
but anyway if your new to this and just want to feel things out, come back to this later, because rendering does not help your models just makes them look better!