You can certainly use the same ID, in fact that's probably the best way.
Many of your apps will transfer over, however only ones that had a + by the download button are universal apps, so they'll scale up for the iPad screen.
I had an iPod first, then the iPad. When I got my iPad I transfered over all the apps, then went through, found the ones that looked good, kept those, got rid of the ones that didn't look good.
You will eventually find that there are iPad apps that will not scale down so will not work on the iPod.
You can use the same ID on both devices and I would advise that so that you can share all of your purchased content on both devices.
You will not have to purchase your apps again as long as you use that same Apple ID on the iPad. Depending upon where you live, music may not be available for free downloads.
Since you don't show your location, you can check here.The new iPad, iOS 6, 64GB WiFi