Hello,
You can try to use procedure bellow:
First of all, you need to create all of the necessary BizForm fields with allow empty value property checked. Then you need to create as many alternative forms (please see
Alternative forms module overview and related topics in the same section for more details) for your BizForm as the number of pages you require. Each alternative form will be configured to show only fields you require to be displayed on that alternative form - page. Then you would need to modify ~\CMSWebParts\BizForms\bizform.ascx web part and add some for example "next" button to it. The aim of this “next” button will be to change Alternative form (viewBiz.AlternativeFormFullName) and also to save the BizForm data (viewBiz.BasicForm.SaveData(string redirect_to_URL)). After first page is saved, Bizform entry is created and you need then just to update existing one using [url= http://www.kentico.com/docs/devguide/bizforms_api.htm]BizForm API[/url] on rest of pages.
Best Regards,
Martin Dobsicek