Typography:

Legibility: Choose classical time-tested typefaces

Serif vs Sans Serif: Serif reads best at smaller sizes, can be complimentary

Font Variance: Too many confuse the reader.

Definition: Fonts that are too similar cause ambiguity.

Readability: Use upper and lower case letters for optimum clarity.

Alignment: Left alignment reads easiest, consider eye flow as it moves down a page.

Emphasis: Use these tools with discretion and without disturbing eye flow.
(Italics/Bold/Size/Color/Typestyle Change)

Integrity: Avoid stretching or distorting type.

Weight: Strive for a sense of balance.

The mac is not a typewriter

Kerning: The individual space between letters.

Tracking: Applying Kerning to the entire word.

Large Text Blocks: Rags