lucy24 - 10:11 pm on Nov 7, 2012 (gmt 0)

Doing it with floats is one way: left, right and default. Another way is to make three divs set to {display: inline-block} with a specified width, and pack all three inside a single bigger block.

The widths have to add up to less than 100% even if you've ruthlessly cut out all margins, padding and borders. Don't ask me why; I just know what doesn't work.

Make sure you think about what will happen if the viewport isn't wide enough to hold all three of your boxes with their content.