The easiest way is to use Handbrake Lite (not Handbrake) to import/convert your movies and then manually drag or add them to your iTunes movie library. Done. On your next sync they will load into your iPod.
I can't wait for the day iTunes will do this natively. Why not?? They would warp it in DRM and only allow it to play on 1 device that is tied to an iTunes account.
Handbrake supports batch conversions. It's called the "queue", but you have to rip the DVDs to a HDD first .. which is something that you'd probably want to do anyways.
As for windows, you could try Handbrake for Windows.
My personal work flow is to rip the DVD first using MacTheRipper on a Mac or DVDfab Decryptor on a PC. Then I run the VIDEO_TS folder through Handbrake.