Designing a layout begins by developing a basic grid. Think about it in terms of slicing up your page. Designate specific areas for titles, sub-headers and content. But most importantly: leave strategic areas of white space. White spaces guide the eye (and mouse) of your visitor.
Detailed Layout
Now that you have a basic layout grid, it is time to go in and build up your hierarchy. Start thinking about justification and the "color" of the type as you introduce different headers, subheads and so on. Don't panic, if your design begins to look corporate (or like a newspaper). That is only because there isn't any imagery.
Type
See how the word "Headline" stands out against the gray color of the paragraph below it?
At this point, you should start thinking about this as well as how your other "text boxes" interact with each other.
Specifying and adjusting your type is a fairly technical process.
You can do a lot of dramatic effects by simply changing or contrasting the point size, tracking and line spacing.