Rules of Thumb for Web Design?

almost 4 years ago from , Beach Bum

I see a lot of general advice out there but I'm looking for are any articles for specific rules of thumb for all aspects of web design - margins, typography, colors, visual hierarchy..

Things like font line height should be 1.5em, don't use more than 2 font families, etc.

Example: http://designforhackers.com/blog/font-sizes/