How to prevent drupal 7 from saving a node I have a dummy form that will act as a main switchboard for all my content types. For example:

My starting point in the form fill up process starts with the 'Enter basic categories' node type where user specifies the categories in a taxonomy hierarchy:

Classifieds
&nbsp;&nbsp;-Autos
&nbsp;&nbsp;&nbsp;&nbsp;-Aston Martin
&nbsp;&nbsp;-Computers
&nbsp;&nbsp;&nbsp;-Desktop
&nbsp;&nbsp;&nbsp;-Laptop
&nbsp;&nbsp;-Jobs
A user then selects any of the terms and the page now redirects to the appropriate content type form, e.g. computers_node_form

The thing is that Drupal saves this Enter Basic Categories Node Form data that I no longer needed.

Is there a way to cancel or prevent Drupal 7 to save the first content type before the redirect? Any suggestions?
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.