The key things to take away from this article are:

• Set structure in percentages. This includes content areas, sidebars etc.
• Set type in rems with a pixel fallback for older browsers. This gives us a great amount of control with added scalability.
• Set type-related items in ems so that paddings et al scale with the font-size.
• Set line-heights in relative units. Or, even better, with no units at all.
• Don’t set measurements on components at all. They should remain fully fluid and ‘just work’ wherever you drop them.