You can transfer the Music on your iPod to your new computer and iTunes library by following the instructions that apply by clicking the link below for instructions:
However, for moving your other media, you have to move it from the iTunes library on your old computer to your new computer. This process is different for Windows to Mac or Windows to Windows than it is for Mac to Mac. We would need to know what you are coming from and what you are going to in order to provide an appropriate link. Please let us know....