This is a lot like a chemistry experiment and over time you will become more fluent in the terms and techniques used in rendering. This document is by all means not exhaustive. It's designed to give you hints and locations of feature choices and explanations. It can also serve as a handy place to search for solutions to problems you might have.
Something more specific? Try our forums for users.
Something seems broken? Take a look at the support page.
How can I get started, I know a little bit already about lighting and rendering.
Try our Best Practices page using the Cookies and Milk example or our Robot Training scenes to refresh your memory and maybe get inspired. You'll find even more specific examples on the community site.
How do I make something look like glass?
We use a PxrCamera projection to render realistic effects from a virtual camera. These can be anything from depth of field effects to distortion from imperfect lenses. In bridge products we map their own controls to our projection plugin, just use what's builtin or under the RenderMan options.
Can I get caustics from RenderMan?
Not directly, but we make use of light filters here at the studio for this task. Experiment with them, we tend to use the ramp light filter and IntMult filter for this task.
What do I use to create variation for things like leaves, robots, storm troopers, etc?
We have a few options for that, try some of these based on your needs or workflow: PxrMultiTexture, PxrRoundCube, PxrVary
My textures are blurry or mushy, can I solve that?
Certainly, trace sets are useful for that and more. Control shadows, reflections, even subsurface interactions with these controls.
How do I add dust or labels to something?
You should use the PxrLayerSurface when you know you're going to have a layered effect. Take a look at the main page with links to tutorials.
My displacement seems wrong, how can I fix that?
We cover this for Mudbox and Zbrush exports. Also take a look at layering displacements (best used with vector displacement). Got holes showing up? Try using watertight dicing option on your object shape and check your UVs for bad layout or flipped edges. Polygons with hard edges/normals might also come apart, subdivide these.
How do I use the Denoise feature?
Take a look at the workflow page for Denoise. The pages linked under it explain more about the tool and options in bridge products.