‘This is a simple trick to overlay a grid or a mock-up over a page you're styling. It will also allow you to edit content directly in the browser to see how your layout behaves depending on various lines of text.’

This may be worth looking into. I waffle on whether this sort of thing is ultimately a good decision — you're relying on someone else's framework, it takes a while to learn and master, and once you decide to go with it you're essentially stuck with it. But isn't that the case with any pseudo-framework developed for a website design? I should test this on a little project.

Finally, a tutorial for getting size and line height to render and scale exactly the same in all browsers for a given font size. Requires some basic math in the stylesheet.