If you're using Advanced Render, Cinema's built in rendering engine, you can't beat this old but very informative
tutorial. It does a great job of introducing the basic concepts.
There are also some great video tutorials produced by
3DFluff. Volumes 1, 2, and 4 are appropriate for architectural work.
If you specifically want a book, the
Cinema 4D Workshop by Arndt Koenigsmarck is very clearly written, but it covers several other subjects in addition to rendering. Finally,
this book sounds great but I haven't read it. Hope this helps.
Jack