OpenBSD: The FAQ is available in PDF and text form -- same thing for NetBSD and FreeBSD

Look under /pub/OpenBSD/doc/obsd-faq.pdf and /pub/OpenBSD/doc/obsd-faq.txt on your nearest FTP mirror. The thing's 227 pages long in PDF form.

The 998-page FreeBSD Handbook, compressed in its various forms (including PDF, Postscript, text and RTF), can be found under /pub/FreeBSD/doc/handbook
from your local FTP mirror.

It's especially nice to be told to RTMF when the manual in question is as good as these two. And these are free books. I do recommend, especially, Michael Lukas' new FreeBSD book as a very valuable addition to your cadre of references. I'd love to see an update to his OpenBSD book, which now is out of print but still available for sale in PDF format.

From reading the OpenBSD FAQ, I've already learned that OpenBSD has an interactive mode for pkg_add, invoked with -i:

$ sudo pkg_add -i dillo

So you don't need the exact name of the dillo package; using -i would give you multiple, or a single choice (depending on whether or not there's more than one package with the name in question) without having to know all the extra letters and numbers at the end of the file name. Like I've said before, package management is very strong in OpenBSD.

It's also possible to use multiple mirrors, or a mirror and a CD-ROM in your PKG_PATH variable.

Again, in most Linuxes, this kind of thing is more hidden from the casual user. It's not all that hard to have a greater hand in setting these things up, and the understanding you gain by doing so is very valuable. (And I'm more confident using this kind of package management than pkg_tool in Slackware, which does a great job of installing packages but doesn't handle dependencies. I've used slapt-get (via the Gslapt GUI), but I'm a little wary about dependencies there, too.)

Also: OpenBSD includes a screensaver by default in X.

And: NetBSD has a terrific Guide that numbers 376 pages in PDF form. And now that I'm running the NetBSD live CD -- which has been out since 2006 but which I've also never heard of before today, I'm anxious to give NetBSD 4.0 another try.