Hey Beracah,
Your best bet for any kind of fabrication books would be on Amazon.com. Type "Fabrication" in the search window & see if there are any books available. Also, you may want to type in "Tool & Die", "Production Design", "Jigs & Templates" and you may find something that would pique your interest. I have been in production design for 30+ years and had the good fortune to work with some awesome tool & die gents who allowed me to probe their minds. Most fabrication jobs that are multiple items will require jigging or fixturing that will produce what I call "repetitive consistency". These types of apparatus are designed from a finished product. You simply build a jig or fixture around the finished product to be able to then place part material in a fixed location and weld together. It takes years to learn and some applications will cause you to look for the Excedrin. The secret is to keep it simple....simple always works the easiest and best.
Hey tmc,
If you type "kingsmetals.com" in a Google search window, it will take you to King's Architectural Metals. They specialize in handrails and fittings of every shape and size to construct some beautiful handrails. I believe they have a catalog and info you may find useful...
Good Luck to both you gents.....Denny