Most (if not all) commonly distros include wizards for setting up storage encryption and/or LVM (and optionally LUKS). Given that this is something that takes place along with disk formatting and filesystem making, I think the handbook should mention this and either include skippable sections, or at least links that deal with the subject matter.
I don't mind linking to external resources on this (like the Gentoo Wiki DM-Crypt LUKS page) but currently I'm not sure this will give a positive result for users. The document on the wiki isn't aligned with the handbook installation instructions which might confuse users currently.
http://linux.arantius.com/gentoo-encrypted-root-with-luks-and-lvm is usable, but maybe there should be an official handbook section that is aligned with the rest of the install.
agreed with @swift. note that we already have installation guides for using LVM, and our documentation touches on luks in a few other places. http://www.gentoo.org/doc/en/list.xml?desc=1 due to the way our handbooks are programmed, we can't do procedural content with skippable sections...not for something as invasive as the software you've mentioned, where everything changes. if you can come up with some sample patches or suggested text (and where it should be placed), we can revisit those ideas...but until then, there's not really a way to do this besides our existing separate guides.
