There are five basic types of fonts: serif, sans serif, cursive, fancy and monospace. Serif and sans serif fonts are used to present bodies of text. If you want to communicate qualities such as warm, personal, artistic, stately, traditional, conservative or intellectual then use serif fonts on your website. If you want to communicate qualities such as technical, cool, clean, crisp, youthful, modern or uncluttered then use sans-serif fonts on your website.
The next step is to find common fonts. Different computer have different operating systems and thus different fonts. Some of the fonts can look better on PC's, like Arial and some look better on Mac's, like Helvetica. There is though one sans-serif font (introduced 1996) that looks good on both PC's and Mac's and it's Verdana.
Text Sizing
The most common font size for main text is 12px but it's usually to large for websites. The size attribute varies also depending on font-family and if the font is serif or sans-serif.
Suggestions for different text elements;
Text: 10px or 12px
Main Headings: 14px, 16px or 18px
Sub-Headings: 12px or 14px
Captions: 8px, 9px or 10px
If you design for people with visual impairments or elderly avoid text size smaller than 10px.
Text Styles
There are seven different attributes you can use to enhance your text and help you better get through with your message. Those attributes are:
Plain - used for main body text, preferably on light colour backgrounds, and large headings.
Bold - used for emphasis in headings, sub-headings, key words, small blocks of texts and text menus. Don't overuse this attribute.
Italic - just as bold, this attribute is suitable for emphasis in key words, quotes, photo credits, captions and titles. Italic can be difficult to read if overused.
Capital Letters - apply basic grammar rules when using capital letters. You can use either capital or lower case first letter in your headings.
CAPS - used only for very short words.
Underline - should be avoided on websites due to the risk of being confused with links.
Colours - used to attract attention or to emphasise a word or group of words. Don't overuse as the website can become cluttered.