How to Highlight individual words? In what way did you want to highlight the words? With a yellow background? To do that, add this code in the source editor: <span style="background: #ffff00;">words to highlight</span> If you are using KompoZer the highlight tool is next to the color tools. One box is text color one box is background color and the pin with color under it, is the highlight color color boxes in upper left of Kompozer. So highlight your words and click on the pin/color and pick your color.
you have suggested a very good way of doing this.This method has already been implemented in most of the standard blog templates.You can also use font tag and then can style it to achieve this.Let me know if I am wrong.
it is better use this way: this code in xhtml <span class="highlight">words to highlight</span> and this code in css .highlight{color:#000;background:#ff0;}