Creating a multi-page form is probably much simpler than you might suppose. You may do it by just creating a sequence of form folders that each link to the next.

The basic procedure is:

• Create your sequence of form folders, typically all in the same normal Plone folder;
• On all but the last form folder, turn off all action adapters and set the Custom Success Action override to "traverse_to:string:id-of-next-form-folder";
• On all but the last form folder, set the Submit Button Label to something like "Next" and turn off the cancel button.
• On all but the first form folder, set the Exclude From Navigation flag in the properties tab;
• In each form folder, create a set of hidden form fields matching all the fields in all the previous forms;
• In the last form, turn on your real action adapter(s).

As your user moves from form page to page, input will be automatically saved in the hidden fields of subsequent pages.

A Note on Hidden Fields: The hidden flag is not available for all form field types, but you don't need it. String, Text and Lines fields are adequate to carry all the basic data. Use a hidden Lines field to hold multiple selection field input, string or text for the rest.