Q: Is there a limit to the number of computers your can link to your ipod

Five computers can be authorized per Apple ID. A total of 10 iDevices can be associated with each computer.

But you can deauthorize computers that you no longer need, or deauthorize all and then reauthorize the ones that you want to use.. See Deauthorize your computer using iTunes - Apple Support.

You should backup your existing library and copy it to the new computer when you get it. See Backup your iTunes for Windows library with SyncToy.

If you don't have all of your content on your current computer to backup see Recover your iTunes library from your iPod or iOS device.

tt2

Perhaps I've misunderstood your question, but if you are asking if you can connect your iPod to two or more different iTunes Libraries (on two computers), then no, you cannot.

Your iPod is designed to Sync with one iTunes Library. If you attempt to Sync it with a second one, the content from the first one will be removed, just as with your iPad.

As tt2 has mentioned, you need to copy your Library from the old computer and put it on the new one. Then connect the iPod to the new computer and wait for the Syn of the new computer's Library to connect with the iPod.