Issue 139 (Christmas 2010) of Linux Format magazine has a 4-page Gentoo tutorial entitled 'Gentoo: Install and use'. Haven't looked at it in detail yet, but it looks to me like it talks you through installing a stable branch Baselayout-1 system, which is much older than the unstable/testing branch Baselayout-2/OpenRC Gentoo/Sabayon systems, but should nevertheless be quite educational.
