After installing the plugin, go to the global jenkins configuration panel (JENKINS_URL/configure or JENKINS_URL/configureTools if using jenkins 2), and add new NodeJS installations. If you wish to install NodeJS from a nodejs.org mirror, select the "Install from nodejs.org mirror" option, where you can then enter a mirror URL and then install NodeJS just like you would from nodejs.org. For every Nodejs installation, you can choose to install some global npm packages. Since 1.2.6 you could force the installation of the 32bit package for the underlying architecture if supported. If the package is not available the build will fail.