For first-time Gentoo users, I strongly suggest using genkernel instead of plain make menuconfig. By default, genkernel will include all drivers it thinks is required.
If you have the time, re-run genkernel and gradually reduce the drivers you don't need, edit grub.conf, and reboot. Keep reducing. Note the settings (get the .config file).
ThenIn my case, I chose to do a re-installation, this time use the .config file and go straight to make. Not necessary, but I just dislike having many half-baked kernels lying around, plus some (possibly irrational) dislike of having to boot initrd.
(Well, at least that's how * I * did it. Takes time, but ultimately satisfying :-) )