Preprocessors (aka precompilers) can make your life much easier when building a website. To be more specific the preprocessors eliminate code repetition and provide all sorts of yummy time-saving and code-saving features.
Watch this recorded live session
Look over SASS’s getting started guide, which provides a brief look at its awesome features and then watch this 20-minute Sass Crash Course:
In this section you can find a lot of helpful links to other content. This is a supplemental material for you if you want to dive deeper into some concepts.