If you have a MailChimp mailing list & wish to allow visitors a “sign up here” area on your sidebar, search for and install “MailChimp List Subscribe Form”. Once it’s installed, it will be simply called “MailChimp”. To finish setting it up, go to “Settings”, “MailChimp Setup” to sign into MailChimp’s site and and get your personal API key, which will link your MailChimp account into your website.
Once you’re logged in, you’ll be able to select the list you wish for people to be able to sign into & update the title, text and any fields you’re collecting from visitors. You can also set an “Unsubscribe”, to make it easy for people to drop their name from your list.
Best wishes with your email communication!