Found it on another web:
Do & Donts Typography
- DO NOT use too many different font faces on the page
- DO NOT switch from serif and sans serif fonts multiple times
- DO NOT ignore planning for font increase by the viewer
- DO NOT use Sans Serif fonts for large bodies of text
- DO NOT overuse font replaces like Cufón and siFr
- DO NOT overdo the emphasis in your text
- DO NOT forget to utilize font stacks in your css codes (“font: Helvetica, Arial, sans-serif”)
- DO NOT type in all caps – use text-transform when you need it (text-transform: uppercase;)
- DO NOT forget to use accent characters when needed
- DO NOT – I repeat – DO NOT use comic sans or papyrus on anything!
- DO use line height to your advantage
- DO use the proper text colors on the page background (#F8F8F8 on black / #252525 on white)
- DO use web safe fonts as often as possible
- DO use a proper hierarchy for your pages
- DO make use of a baseline grid
- DO utilize white space as much as possible
- DO keep the use of centered text to a minimum
- DO use shade variations to help areas stand out more
- DO make sure you know about, and use, proper letter spacing for titles
- DO make use of a typographic scale in your css codes
Typography Scale body { font-size: 12px; } h1 { font-size: 5.0em; } h2 { font-size: 4.0em; } h3 { font-size: 3.0em; } h4 { font-size: 2.0em; } blockquote { font-size: 1.5em; } p { font-size: 1.25em; } input { font-size: 1.0em; } small { font-size: 0.75em; }