The Import Users to MailChimp allows you to quickly and easily import all existing users to mailchimp.
Unzip our archive and upload the entire
import-users-to-mailchimp' directory to your/wp-content/plugins/` directory
Activate the plugin through the 'Plugins' menu in WordPress
Go to Options and look for sepearte menu "MailChimp Settings" at the left
4- Enter your mailchimp API key.
5- Select your lists to have your visitors Automatically subscribe to.
6- Select your lists to import all exiting usres.
7- On second memu "Mailchimp Signup Form" Select One of your lists to have your visitors subscribe to and go to Presentation->Widgets and enable the 'MailChimp Signup Form' widget
If you want to signup form an other place at the theme.
so, simple use this
<?php SingnUPForm(); ?> code.
Note: you will need to install the Exec_PHP plugin to use that method of display. It can be found here: http://wordpress.org/extend/plugins/exec-php