Type Legibility and Readability
The designer must also consider the purpose of the work and the expectations of the audience when making legibility choices. The rules of type legibility are guidelines and starting points, not rules to be adhered to blindly.
Books on Typographic Legibility and Readability
These are a variety of books related to legibility in type.
Giving Words Breathing Room
In addition to the specific attributes of a typeface, how it is placed on the page affects its legibility and readability. This includes character spacing, line spacing, and paragraph spacing.
How to Match Type Size to Readership
Choose a font size that your primary audience can read comfortably.
Balance line length with type size for readability. Try these formulas.
Serif vs. Sans Serif
In this article about choosing body copy fonts there are some common assumptions and reasons used for choosing serif over sans serif fonts for readability.
Since Microsoft is behind the move to make Verdana more widely used for the Web, it's only fitting that they have a section devoted to the development of this typeface -- from their Typography on the Web site.
Georgia and Verdana
Typefaces designed for the screen. Daniel Will-Harris takes a close look at these and other screen-friendly type.
Typographical factors that affect readability of text and arguments against the search for the ultimate legible typeface and a look at how we may have outgrown old "rules." By Peter Bilak; from TYP/Typografisch Papier.