There are 5 tabs here that have various sub tabs.
All settings here apply to all pages and are therefore called Global page settings.
Set size and orientation of the pages in Inches or Centimeters. Choose from many A-size standards or other page sizes and specify Portrait or Landscape.
Setup background color, border, margins, header, and footer.
These settings apply to front- and/or back cover pages, mostly only available if a cover page is added to the instructions.
Set a title for your model at the Front Cover page. LPub3D reads the title from the Name meta-command but can be modified too.
Setup an image to use on the cover and apply certain properties for it.
Various content for a front- or back cover
Identify model or submodel by name and display total pieces (=bricks or parts) used in the model
Setup 4 levels of background color for pages or callouts.
These settings also apply to front- and/or back cover pages.
Show the name and/or e-mail address of the author or designer of the model. Content is read from the LDraw file but can be modified too.
Show the URL to the webpage of the author or publisher (creator of the instructions)
Display copyright information.
Display a logo (image) on the Front or Back cover.
Use the standard disclaimer or modify the text.
Show information about the LPub3D version used for your instructions and the LPub3D logo.
Setup Look (Font and Color), toggle show Page Number on/off and placement.
Enable or disable Text Placement.
An example of building instructions using many of these settings can be viewed below and LDraw file downloaded here.