W3 School CSS:  http://www.w3schools.com/css/
CSS Syntax: http://www.w3schools.com/css/css_syntax.asp

Child Themes: http://codex.wordpress.org/Child_Themes
The only required lines are the Theme Name, the Template.

5 minute install: http://codex.wordpress.org/Installing_WordPress#Famous_5-Minute_Install