The FreeBSD Handbook is a comprehensive guide to using and administering FreeBSD, a free and open-source operating system based on the BSD (Berkeley Software Distribution) version of UNIX.
You can access the FreeBSD Handbook online at the following URL:
https://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/
The Handbook is organized into chapters covering a wide range of topics, including installing FreeBSD, configuring the system, managing users and groups, managing disks and file systems, configuring networking, and much more.
In addition to the Handbook, there are also several other resources available for learning about FreeBSD administration, including:
These resources, along with the FreeBSD community forums and mailing lists, can be a valuable resource for learning about FreeBSD administration and troubleshooting any issues you may encounter.