Bold: <b>TEXT HERE  
Example: This is bold text

Italic: <i>TEXT HERE</i>  
Example: This is italic text

Underline: <u>TEXT HERE</u>  
Example: This is underlined text

Change Color: <font color=' COLOR NUMBER HERE (e.g. #FFFFFF) '> TEXT HERE </font>   
Example: This is coloured text

Change Size: <font size='3'> TEXT HERE </font>
Example:  This is size 4 (14 pt)

Insert Hyperlink: <a href='LINK HERE'> TEXT HERE </a>
Example: <a href='http://www.boreded.co.uk'> CLICK HERE FOR BOREDED </a>

Insert Image: <img src=' URL '></img>
Example: <img src='http://www.boreded.co.uk/images/image011.gif'></img>

A bit more advanced
Insert Table:   Begin = <table>     New row = <tr> TEXT </tr>   New Column = <td> TEXT </td>  End = </table>
Example: <table><tr><td>ROW 1, COLUMN 1</td><td>ROW 1, COLUMN 2</td></tr><tr><td colspan='2'>ROW 2, COLUMN EXTENDED OVER 2 COLUMNS</td></tr></table>

Insert Video/Sound: <embed src='URL' width = 'SIZE IN PIXELS' height='SIZE IN PIXELS'></embed>
Example: <embed src='http://www.boreded.co.uk/videos/video011.mpg' width='500' height='400' autostart='false'></embed>

For more information about HTML please use the link below...

http://www.htmlgoodies.com/beyond/reference/article.php/3472851