I discovered the OpenBSD 101 site some time ago, when it was still hosted on WBG, and I cannot resist the urge to give it a little publicity.

Does OpenBSD tempt you, but you are afraid to take the plunge, afraid that this wonderful operating system is too complicated, too obscure for you? Then go and take a look at this address: www.openbsd101.com (In English), and you will change your mind.

And for those who do not yet know OpenBSD: www.openbsd.org

Update (2026): the OpenBSD 101 site no longer exists; the link above points to an archive. For a current alternative, different but in the same spirit: www.openbsdhandbook.com.