In general I find the Linux Multimedia Guide a good reference text with a moderate degree of developer tutorials. The only drawback that I can see is that, like most of other Linux texts, this text does not provide a users perspective on any of the tools listed. If Linux is to ever go beyond a developer's-only platform there will need to be detailed users guides for the various well known applications. POV-Ray for Linux doesn't have a modeller. SCED allows you to preview your image using various renderers.
Modellers create shapes that are independent of the tools used to render the image.
Modellers are great for creating shapes, but the textures applied to those shapes depend on what renderer you use. POV-Ray has its own set of commands that it uses for determining how a texture will look on an object in a scene. For POV-Ray you need to learn the command syntax for describing textures. It may be out of print. This text has a good reference for the 2.2 version of POV-Ray.