What is the easiest way

the best way to transfer your files over a network connected to both your old and new pc.all you have to do is enable file sharing on both pccs give them static I.P addresses and that way just share the folder that has all your music over the network.this method is mega fast and saves you the time of having to moves storage devices.

BUT if you insist on doin it you way here is what you do.
-Go to your my documents folder-itune-itunes music and there u should be able to see all your music and then be able to copy it to your device.
-Alternatively you can just go to start-search and search for all music
when thee search is done select all the music by using CTRL-A
copy all the music using CTRL-C then paste it to your device with CTRL-V and you are now ready to transfer it to your new computer.
It might be a little difficult to transfer the music into the itunes on your new pc.
-So what i recommend is to install the i tunes after u have copied the music onto your hard drive and that way i tunes will automatically scan for and add the music to it library hence saving you the hustle

If you have a USB flash drive that would work just fine & real fast, just copy & past. No hassel creating a CD.
If you do not have a flash drive than a DVD-RW would be my next choice. The DVD can hold up to 4.7GB of data & you can format the DVD-RW & use it again.