The Quickstart is documentation aimed at users of TinHat. If you just downloaded the ISO and want to begin using it, this is where you begin.
Developers, or the curious, may want to look at the other links. TinHat was put together with some specific needs in mind. We made choices that are unconventional, and may seem or be (or actually be) stupid! We document these in our Technical Considerations with our justifications. We invite criticism.
The other section, "How to Cook TinHat", describes how Tin Hat is built. In sum, build scripts are ran in a chroot'ed environment. These are kept up to date with Gentoo and other upstream sources, and the cooking scripts are then run to produce the ISOs.