How do I download to iPad content for Adobe Digital Editions?

I installed the ADE app from the App Store and installed it on my iPad. I then tried to download free sample eBooks from the ADE web site, but all that gets downloaded is something called "URLLink.acsm." This is nothing but a 2KB file that is not seen by the ADE app. No matter which smaple eBook I try to download, all I get is the same URLLink file.

How can I read eBooks on mu iPad with the ADE app?

Thanks.

Howard