Designers make things better for people—Good Design is a matter of visual spacial balance (form) and usability (function) in the appropriate context, where context determines intent.
My pursuit of Good Design has led me through many rabbit holes. Here are the resources I've found most pertinent.
1. Attitude

Zen & The Art of Motorcycle Maintenance
Robert. M Pirsig

Surely You're Joking, Mr. Feynman!
Richard Feynman
2. Form

By Hand and Eye
George Walker & Jim Tolpin

Thinking With Type
Ellen Lupton
3. Function

The Design of Everyday Things
Don Norman

Don't Make Me Think
Steve Krug
4. Process

Change By Design
Tim Brown

The Lean Startup
Eric Ries

Lateral Thinking
Edward de Bono

Prototyping for Designers
Kathryn McElroy
5. Human Behaviour

Nudge
Richard Thaler & Cass Sunstein

Thinking Fast and Slow
Daniel Kahneman
6. Technology

How to Speak Tech
Vinay Trivedi

Shaping Things
Bruce Sterling
7. Business

The Personal MBA
Josh Kaufman

Business Model Generation
Alexander Osterwalder & Yves Pigneur
8. Complexity

Thinking In Systems
Donella Meadows

How to Make Sense of Any Mess
Abby Covert
9. Research

Just Enough Research
Erika Hall

The Field Guide to HCD
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