Specifying Fonts

The best way to learn about fonts is to play with them. Make up a test stylesheet. Attach it to a document. And see what happens. Then change something and take another look. Here's an example of the type of test stylesheet you might make (you could copy and paste this one as a template):

body {font-family: arial, geneva, sans-serif; font-size: 125%; color: navy; text-align: justify; }

p {text-indent: 35px; }

dt {color:#FFFFFF; background-color: navy; text-align:center; padding: 5px; text-transform:capitalize;}

dd { margin-bottom: 5px; font-size: smaller;}

h2 {font-family:Georgia, "Times New Roman", Times, serif; color: maroon; font-variant:small-caps; text-align: center; font-size:larger;}

These following list explains the the properties that control the appearance of fonts.

font-family
The name of the font family. You can try for some specific fonts (Century, "Cordia New", "Xmas Lights BRK"), but be sure to offer a generic choice as well (serif, sans-serif, monospace not monospaced or monotype or mono, cursive or fantasy). If you have defined the font-family in the body definition, you do not need to redefine it UNLESS you are making a change. For example, you want lists to be set in "Times Roman" while the remainder of the document obeys the sans-serif specified in the body rule.
font-size
Try px (pixels), pt (points), em (ems). Be sure to view your HTML document in different browsers and on different computers to see how the specs work. You do not need to specify a type size for every tag. The browser will know that H1s are larger than H2s, and that H4s are larger than links. When you make a decision to break from the norm and make your links larger than your H4s, then you should specify a size.
font-style
Your only choices are: normal, italic or oblique. And there usually is not much difference between italic and oblique. You do not need to specify normal for every page element UNLESS you specified italic or oblique for the body font-style.
font-variant
Your choices are normal or Small-Caps.
font-weight
normal, bold, bolder, lighter, 100, 200, 300, 400, 500, 600, 700, 800, 900
color
You may want to stick with the 216 web-safe colors. Use one of the many color charts available on the web like this one or this one. Colors can be specified in r,g,b format, hexadecimal #000000, or specific names spelled exactly as you see them on the chart. Go here for more about color, plus more color charts.

Check in more than one browser. I recently created a page that appeared lavender in Internet Explorer and midnightblue in Firefox. Web safe colors should appear the same on every browser.
background-color
You can specify a background-color for any text element.
background-image
You can specify a background image for any text element.
text-align
left, right, center, justify
text-decoration
underline, line-through, overline, blink, none
text-indent
Specify a number followed by a unit of measure: 10%, 5mm, 0.5in, 10px.
text-transform
UPPERCASE (ALL THE LETTERS),Capitalize (The Initial Letters), lowercase(all the letters), none (display as typed)