Learning how to use cascading style sheets to control the presentational features of page content allows for more flexibility and reduces the amount of page weight prevalent with nested tables and depreciated tags. By separating content from presentational features you can save yourself a lot of work while also providing your client's with several benefits...
So to get you over the learning curb "hump" and on your way I'm going to make this as simple as possible by showing how "you" can create a valid cascading style sheet quickly and easily by breaking it up into the basic necessary component parts needed to create a web page presentation.
Note: this demonstration is by no means an exhaustive lesson plan on all the rules and properties associated with CSS syntax. It is an introduction to cascading style sheets inspired to show the simplicity and over all benefits of their use.
For specific information on the rules and properties associated with cascading style sheet syntax you can visit: http://www.w3.org/Style/CSS or if I may suggest; check out "Cascading Style Sheets 2.0 Programmers Reference" written by Eric A. Meyer, which provides complete in depth details about cascading style sheet 2.0 syntax, it is a great pocket book reference for website designers - developers.
What might be of interest to developers is how much time can be saved in the development of server side code that utilizes cascading style sheets to control presentational features of web pages created by the server. For example:
PHP that rely's on a style sheet for its presentation:
PHP that does not rely on a style sheet for its presentation:
It should be obvious from the above example how much typing would be eliminated in code development that utilizes a cascading style sheet.