You should only use a selected collection of fonts with your web pages.  The main reason is that not all fonts are available on every computer.  For example, you have a font on your machine that makes your web page look outstanding, but a user on the Internet might not have the same font.  When they view your page, the will not see the same thing that you do...

What fonts to use

The following is a list of fonts that are safe to use:

Arial
Times New Roman
Verdana
Courier New
To change the font face, you use the face attribute of the font tag.

<font face="Verdana">This is Verdana</font>

Changing the font size

You can also change the size of the font.  To do this you use the size attribute of the font tag.

<font size="1">Size 1</font>
<font size="2">Size 2</font>
<font size="3">Size 3</font>
<font size="4">Size 4</font>
<font size="5">Size 5</font>

Changing the font color

The color of the font can be changed either by modifying the body tag or by modifying the font tag with the color attribute.

<font color="red">This is red</font>

Will produce the following:
This is red

Changing the font style

You can change the style of any font through emphasis and enhancement tags.  These tags include, bold, underline, and italic.  Although underline should be used rarely since it also signifies a possible link.

<b>This is bold</b>
<i>This is italic</i>
<u>This is underlined</u>

Will produce the following:

This is bold
This is italic
This is underlined