Help with iTunes and my iPod!!!!

[londonlad888]

Ok here goes... basically to free up some space on my PC I bought an external hardrive and basically transferred the iTunes folder with all my songs and videos on it to the external hardrive, and deleted the folder on the PC.

Now when I open iTunes, my songs don't come up anymore.
What I want to know is, if I sync it the iPod, will it automatically erase all my data on there?

[londonlad888]

I want to update my iPod with new songs but at the moment am unsure how to go about it.