I will begin a thorough study of the OpenBSD and FreeBSD, which are the most complete books?
I found these, which are the best?
As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or specific expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, see the FAQ for guidance.
Check out The Complete FreeBSD by Grey Lehey, available for free. Greg is a good guy and used to be part of the FreeBSD core development team. Maybe he still is, I'm not sure. The book is probably a bit out of date, it seems was last updated in 2006, but it would be a start at least.