Go to Window > Settings/Preferences > Plug-in Manager. Go through this tutorial to set up the mental ray Plug-in
This tutorial shows you how to render efficiently (speed & minimum issues). It is best to convert CAD data from surface/solid data to polygons.
Preferences for modeling can be set in the Preferences window. From the menu, go to Window > Settings/Pref- erences > Preferences. Go through this tutorial for more details.
Basic Polygon Manipulation.
This tutorial shows you how to use the artwork on a layer to produce 3D objects.