While the other answers are certainly good ideas, you may also want to consider persisting the intermediate data to your database between each page. So, submitting the first page would create the new row, with the columns relating to contact details populated, and a status column set to a value indicating that the submission is not yet complete.
The second page would update that record in the database. The third page would also update the record, as well as the status flag to indicate the submission is complete.
The main benefit to this is that the user can walk away after the first (or second) page, and then return to it later, even if he had closed his browser and his session had expired. (As long as he has a unique URL to return).
This approach might not have a lot of benefit if you are only collecting three pages of data, but if you had many pages, the ability to leave and return later might be more important.