How to prevent drupal 7 from saving a node
So basically, you don't want a form for content entry, but you want a form to streamline the user navigation - right?

You can probably alter the node form (implementing hook_node_submit for instance) to stop it from saving data, but I recommend against it. The essence of a node is that it is site content, so it doesn't make sense to have a node form that doesn't save a node to the database.

You can build a custom form that does exactly what you want it to do by implementing hook_menu (to choose the url for your form) and a custom form generating function. See form_example.module for examples of custom forms.