When you install the CMC component, we also install a frontend module that you can use to display a newsletter subscription form on your site. Go to Extensions -> Module Manager and in the list find the CMC - Newsletter subscription module.
If you don't find the module in the list click on New and then select the CMC - Newsletter subscription module
The basic parameters of the module should look something similar to this:
You are already asking - what is the field "field mapping" for? Your newsletter form generally requests information from the user that you could possibly have. For example for logged in users you have their email and name. So why should you ask your login users to type all this? You could prefill the form with their e-mail and name and just ask them to hit the submit button. This is where the field mapping comes in handy. There is no way for us to guess which field in mailchimp corresponds to the user object in Joomla. That is why we need you to provide this information manually. For example here is a standard configuration that would fill out the email, first name and last name:
EMAIL=email FNAME=name:0 LNAME=name:1
On the left you have the field tag as specified in Mailchimp. On the right you have the corresponding Joomla user property. Maybe you are already asking yourself - what is the 0 and the 1 after the name? Well, in Joomla the first name and last name are stored in the same database field. We take the value in this field, we create an array out of it. 0 is basically the first value in the array, the 1 the second. So in our case 0 is the first name and 1 the second name.
You need to select a list from the drop down field. Once you do this the page will refresh and you'll be presented with the fields and interest groups options for your list.
Select the fields you want to show in the frontend and click on save once ready.
Please make sure to select all the fields that you've marked as required in Mailchimp. Failure to do so will result in not working subscriptions as Mailchimp will refuse to subscribe the users to the list, because some fields are missing.
Depending on the fields and interest groups that you've selected the module will display different options in the frontend. Here is a screen shot of a module that has only the Email, First and Last name fields selected