To be honest, I feel like mwl is being a tad negative here: OpenBSD and OpenSSH man pages are excellent documentation in and out of themselves. Our dear Mister Lucas here has a knack, however, for writing simple documentation that mix humour with serious technical knowledge.
For example, I was able to find a lot of answers in the man pages, asking myself questions but the technical explanation I find in his books made me go "Aha! That's why!"