How to create a free download signup?

I want to offer a free downloadable white paper relevant to my site's topic (college sports recruiting).  The goal of course is to create a mailing list of people interested in the subject.

I feel like this might be a laughably simple question, but I'm new to all of this.  Is there a plugin for this, or does the system have the capability built in?  I have a Mailchimp account and I suppose I'd want to integrate with that somehow, but I'm open to other options.

- Pat