Unfortunately the zip files are only for those that have purchased the book have you tried posting comments on his site. I can't find any contact info there but it does look like he actively responds to the comments he receives.
When you say unzip are you trying to unzip these on Windows? It would be best to try it on the Pi and copy the files over.
You would download on the Pi with wget an example is below:
Code: Select all
wget -U midori http://www.url.com/example/files.tar.gz
tar -zxvf files.tar.gz
Instructions for any platform can be found here if the Pi isn't connected to the internet.
If the file is corrupt only the Author can help you out and I don't know if they are a member on this forum. If they aren't you might suggest they join
http://www.raspians.com - always looking for content feel free to ask to have it posted. Or sign up and message me to become a contributor to the site. Raspians is not affiliated with the Raspberry Pi Foundation. (RPi's + You = Raspians)