Verdana was designed by Microsoft in 1996. Its purpose was specifically for screen use. The absence of serifs and the wide spacing make this font a popular choice for the Web.

Helvetica (for MAC) and Arial (for MAC and Windows) is a common font style created over 50 years ago by Swiss designers. Although two different fonts, they are similar in properties with Arial being created by Microsoft as their version of the style. Arial and Helvetica are one of the most widely used sans-serif fonts.

Trebuchet MS was developed for screen use and is common on Windows and MAC systems. It is popular for large headings and some consider it not quite as legible as Verdana for normal size print. It's best to try it out and see what you think!

Lucinda Sans Unicode (Windows) and Lucinda Grande (MAC) were not created for the Web, but are remarkably legible when reading on screen. Lucinda Grande is the font choice used on MAC operating systems. They are considered the most calligraphic of typefaces within the sans-serif family.

Times New Roman (Windows and MAC) and Times (MAC) are primarily an offline print based font that is approximately 80 years old now. It is not the best font for screens but often a good second choice in your CSS file because it is such a prevalent computer font.

Georgia is a font commissioned by Microsoft; again it was made especially for the screen. Although a serif font, Georgia tends to work well for screen viewing of small and larger text. Designers often substitute Times New Roman with this font due to its preferred web viewing properties.

Palatino Linotype (Windows) and Palatino (MAC) were developed over 60 years ago and are not screen fonts, but they render very well for web use. Microsoft distributed a clear imitation of this font; they called it "Book Antiqua".

The previous typefaces are recommended fonts to use for your main body text. However, there are methods for being able to show fancy custom fonts in your web pages, allowing all of your site users to view them without the need to install the fonts on their system.

If you are looking for examples of what various fonts look like on your screen, take a look at the TYPETESTER online tool at http://www.typetester.org/. This type tool allows you to include your custom text, and then format this with a variety of font and size options, viewing the output on your screen. There are many tools available that do this, but TYPETESTER is a great example of them: