You must remember this...

Rules of thumb for attractive, easy-to-read documents.

Computers in Communication
Boston University College of Communication
Copyright © 1996 by Professor Jim Lengel

Fonts

Use a serif font for body text, sans serif for titles.
Use system fonts (Chicago, Courier, Helvetica, Palatino, Times, Symbol.)
People read best with 10 to 12 words per line.
Line spacing between 1.25 an 1.75 is easiest to read for body text.
Don't mix more than two fonts or two sizes on a page.
Keep the space between words consistent.
Never use all caps.
The simpler the better.

Contrast

Make sure titles contrast with body text.
Achieve contrast with size, weight, font style and separation.
Use italics for emphasis within body text.
The simpler the better.

Space

Leave plenty of white space around the edges.
Build your page around a single axis, or at most two axes.
Make your document balance, from top to bottom, right to left.
Separate paragraphs with line space or indents, but not both.
Use the mountains to "stand back" and view your page a a whole.
The simpler the better.