The is an old basic tutorial, showing how to light, render, and composite a 3d character into a background plate within Maya. There are more advanced methods for generating a composite, but this is a great way to make sure that your lighting and camera angles work relative to the desired background. It also demonstrates a method for capturing shadows that correspond to the background perspective and objects (29min).
More Maya tools and creative discussion are available in my interactive iPad books about Maya's production tools. http://itunes.apple.com/us/artist/jeremy-a.-parrish/id507724058?mt=11