iTouch or iPod Touch? One is a phone, the other a portable multimedia device.

For iPod Touch see How to transfer music to my iPod (& iTunes) {click on link} & check the tutorial videos for iPod. BTW I highly recommend using the Manual Updating of the iPod, see the lower posts on that page.

For iTouch, I am guessing you connect it to your computer via USB cable, drag & drop the songs to its icon. Hopefully you will have an instruction booklet / Manual that came with it to explain how to add music.