Not a bad shallow introduction to the package structure, but it leaves out more than a little, and doesn't address compiled software at all.

Fortunately, Debian has extensive documentation. It's worth a look for anyone wanting to build packages suitable for publishing.

https://www.debian.org/doc/devel-manuals

The New Maintainers' Guide might be a good next step for understanding more use cases and available tools.

The full Guide for Debian Maintainers is more up to date, including relatively new tools like dh that considerably simplify packaging software that uses common build systems.