@LukeAlmighty Correct, you'd need a book about that size to fit all the source code of the kernel, Linux and you do need to read the source of Linux in order to determine how to graft a program onto it.
Installing programs on Gentoo GNU/Linux is far easier though, it's just; emerge <program> You don't need to be always online either, portage keeps around recently downloaded packages, plus you can use the --fetchonly flag to download all sources when you want to do some offline compiling. You don't even need the internet at all - someone can send you tarballs on a flash drive via carrier pigeon and you just gotta cp em to into distfiles.