This part will take you approximately 30 minutes.
J. B. Rainsberger, "Putting An Age-Old Battle To Rest". An introduction to, and refinement of, the four elements of simple design.
Corey Haines, Understanding the Four Rules of Simple Design. A guidebook for more deeply learning the four elements of simple design. Read it, but don't use it as a reason not to practise!
J. B. Rainsberger, "Becoming an Accomplished Software Designer". A relatively quick summary of how intuitive and mechanical decision-making combine to help us design software.
Martin Fowler, Refactoring: Improving the Design of Existing Code. Another of the ten classic books that needs to be on every programmer's bookshelf.