Quick Installation Checklist

Bios/MBR
In this example we create 3 partitions. 128MB /boot, 1024MB swap and rest for /.

Install stage3
Find nearest mirror from: http://www.gentoo.org/main/en/mirrors2.xml

Replace amd64 with your arch.

Create user accounts
Change root password.

Create user.

Configure system
Also edit /etc/conf.d/hostname, /etc/conf.d/keymaps and /etc/conf.d/hwclock.

Set timezone.

Install kernel
Gentoo-sources is vanilla kernel with gentoo patchset. You could also use vanilla-sources. Linux-firmware contains binary blobs needed for some hardware like wlan cards.

Find out needed modules for your hardware. You should enable these modules in menuconfig. You can search module names by pressing "/" in menuconfig.

Install bootloader
Edit grub config.

Here is simple example config.