How can I let users register for a certain node type?
I was finally able to associate the event using the Node Registration module.


  Allows (authenticated and/or anonymous) users to register for events. Events are nodes with certain node types. You can enable registration for any node type and add fields and manage display per type and per node.


The module depends on Value is and Entity as well as Views and CTools. 



What you'll have to do after installation:


Go to admin/structure/types/manage/&lt;course&gt;/edit, where &lt;course&gt; is your course
Enable registrations at the bottom under Registration Settings
Go to admin/structure/node_registration/manage/&lt;course&gt;/fields and add fields to your registration form, as required.
Don't forget to enable the right permissions too for anonymous users.