Getting a white screen after replacing the panel is common, and not a problem. Just soft reset your iPod by holding the power and home button, then once the apple logo shows up depress the power button and continue to hold the home button. Your device should then show on the display correctly. However if you do reset it, anything in its storage will be erased. If this does not work it could be a faulty panel.

Personally I botched it, but hey, the guide was great!