Okay, so I finally figured out the problem with how I had Gumroad set up for the free download. It kept asking for credit card information even for a free item.
I now have it sorted so it won't even ask.
If you didn't try to download the 15 free articles before... now its easy.
These articles appeared in 2007 and 2008. I've sifted through and updated some and only kept the ones that are still relevant today.
Download the 15 articles now.