I learned a few things about quoting in ebuilds today. As of my current understanding it breaks down to two rules:

1. Double quotes for interface strings

DESCRIPTION="Colorizing wrapper around make"
HOMEPAGE="http://bre.klaki.net/programs/colormake/"
SRC_URI="${HOMEPAGE}${P}.tar.gz"
LICENSE="GPL-2"

2. Minimal quotes otherwise

S="${WORKDIR}"/${PN}

src_unpack() {
    unpack ${A}
    cd "${S}"
    ..
}

If everything keeps going smooth my first ebuild will be home in the sunrise overlay soon.