Can I install Snow Leopard over a network? I have a Snow Leopard DMG on one mac, and an empty MacBook I wish to install Snow Leopard onto. I have a Snow Leopard DVD that I can use to get into the installer with, but it's scratched so it won't install.

What are my options for installing Snow Leopard? Over the network? Or putting it on USB stick/HDD? I know I could burn the DMG to a DVD but I was wondering if there were quicker/easier alternatives.
You say the MacBook is empty - does this not have any Mac OS on it?

To install from a USB or HDD you will need to open disk utility and from there select the restore option of the dvd with the hard drive or USB as destination, so if it does not have disc utility then no you can't, you will need to write a CD/DVD.