ben orenstein's simple rules for new programmers, condensed version

orensteins-rules.txt

source: http://codeulate.com/2013/08/simple-rules-for-new-ruby-programmers/

Short methods are vastly superior to long methods.
Short classes are vastly superior to long classes.
Code that is easy to change is better than code that is not.
Duplication is the reason that most code is hard to change.
Code written via TDD is vastly superior to code that is not.
It’s extremely important to name everything in your system well.

Be warned

Some fraction of experienced programmers will disagree violently with my recommendations.

This is mostly because most programmers are extremely detail-oriented. The omission of 
subtleties enrages this group more severely than the general public. These rules are 
simple because they are for beginners, but that will not assuage some portion of people. 
They will be angry that these rules are sometimes wrong.