Did some searches on the boards but didn’t really find a easy to read thread about this: our favorite engineering and product design textbooks. For example, Manufacturing Processes for Design Professionals by Rob Thompson is an amazing resource. If you could all post the books you find yourself referencing enough, help me! I’ll try to keep up and update this first post with the resources and links so the information is at the top. 
On a personal note, I’m coming from an ID background trying to do more mechanical design, so engineering type books that I could keep handy would be the most helpful to me. 
I’ll start with my own suggestion:
There’s also a thread about Design Guides here: Great Design Guides
----------------- Books Worth Buying
Manufacturing Processes for Design Professionals by Rob Thompson
Mechanical Engineering Reference Manual For the PE Exam by Michael R. Lindeburg
Process 2nd Edition: 50 Product Designs from Concept to Manufacture by Jennifer Hudson
Handbook of Materials for Product Design by Charles Harper
Materials Selection in Mechanical Design by Michael Ashby
Invention and Evolution: Design in Nature and Engineering by Michael French
Mechanics of Materials by James Gere (preferably a version from before he passed away)
Engineering Design Methods: Strategies for Product Design by Nigel Cross
