Use the USB cable that came with the device. Your computer should recognize your device automatically. If your computer does not automatically open iTunes when you plug in your iPod, you will need to open it yourself. Make sure that your iPod appears in the left frame listed under DEVICES. Click and drag the video file that you just downloaded into your iTunes library. You can drag it directly to the library icon and it will be added to the Movies section of iTunes. Once your video has been added to your library, you can sync it to your iPod by selecting the Movies tab of iTunes. Check the box that says “Sync movies” and then choose the movie from your list of available videos. Once the sync process is complete, select your iPod in the DEVICES menu, and click the Eject icon next to the name. Once you have ejected the iPod, you can remove it from your computer.

TL;DR in Chinese:
连接iPod到计算机。 打开iTunes。 把所下载的视频添加到你的iTunes媒体库。 同步你的iPod。 等待同步完成。