These ebuilds come from http://git.overlays.gentoo.org/gitweb/?p=proj/gnome.git;a=summary.
If you have some problems, go to the official site first.
make : Standard tool to compile source trees ( http://www.gnu.org/software/make/make.html )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a gnome
For Paludis use this rsync : rsync://gentoo.zugaina.org/gnome-portage
If you have a problem : ycarus(-at-)zugaina.org