Subject
Printing -- Style manuals books
8 free books about printing -- style manuals, free to read online. Chapter 1 of any book is free, no account needed.

Abbreviations and Signs
A Primer of Information about Abbreviations and Signs, with Classified Lists of Those in Most Common Use
Capitals
A Primer of Information about Capitalization with some Practical Typographic Hints as to the Use of Capitals
The Uses of Italic A Primer of Information Regarding the Origin and Uses of Italic Letters
The Style Book of The Detroit News

The Author's Printing and Publishing Assistant Comprising Explanations of the Process of Printing; Preparation and Calculation of Manuscripts; Choice of Paper, Type, Binding, Illustrations, Publishing, Advertising, &c.; with an Exemplification and Description of the Typographical Marks Used in the Correction of the Press
