Design HTML / CSS

Example HTML
<!DOCTYPE html>
<html>
  <head>
    <title>This is the title of the page.</title>
  </head>
  <body>
    <p>This is a paragraph.</p>
  </body>
</html>

Incomplete list of HTML tags

Tag nameWhat it doesHow it works
<!-- -->creates a hidden comment<!-- hidden comment -->
<!DOCTYPE>tells the type of document<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<a>Creates active links to other web pages<a href="http://www.google.com/" title="title of page" class="CSS class" id="CSS identifier" style="CSS expression">text to display</a>
<abbr>Creates an abbreviation<abbr title="this is an example abbreviation">example of</abbr>
<b>Creates bold text  <b>bold text</b>
  Also accepts classstyle, and id parameters.
<i>Creates slanteditalicized text  <i>italicized text</i>
text here<br />Breaks (wraps) a line of text  <br />wrapped text here.
<s>Creates a line through text  <s>line through text</s>
<u>Underlines words and sentences.  <u>Underlined text</u>
<H1>Changes the font of a word to 24  <H1> FONT 24</H1>
<H2>Changes the font of a word to 18  <H2> FONT 18</H2>
<H3>Changes the font of a word to 14  <H3> FONT 14</H3>
<H4>Changes the font of a word to 12  <H4> FONT 12</H4>
<H5>Changes the font of a word to 10  <H5> FONT 10</H5>
<H6>Changes the font of a word to 7  <H6> FONT 7</H6>
<script>Creates a script in the webpage  <script>document.write("Hello World!")</script>
<table>Creates a table  <table><tr> <td>10</td> <td>20</td> </tr><tr> <td>30</td> <td>40</td> </tr></table>
Example CSS
p {
  color: blue;
  font-size: 120%;
}