A good simple article on which CSS style will apply to which part of the webpage - kind of like the order of operations in grade school math =)
http://academ.hvcc.edu/~kantopet/css/index.php?page=css+inheritance&parent=using+css
A good article on efficient CSS, so that you don't need to put class attributes everywhere.
http://www.apaddedcell.com/21-ways-streamline-your-css
Child selector example (there is no parent selector):
E > F Matches any F element that is a child of an element E.
tags: css, efficient, style,