The Persistence of Vision Raytracer Home Page is where you can get POVRay (obviously).

The Internet Ray Tracing Competition is a bi-monthly raytracing contest.

You can get free textures from the following sources:

Textures
POVRay Texture Library
Texture Land

An excellent modeler (although it's not free :( ) can be found at the Moray Homepage.

A great spline based modeler (it IS free) is hamaPatch.

The King of Include files for POV is clearly Chris Colefax. Check out his City Generator as well!

Some more POVRay links.