A significant amount of your modeling time should be allocated to discussions with the client's management. People are generally apprehensive when they're called into discussions with professionals, so you will need to allay their fears and create a non-threatening environment for your discussions. You need to make them understand that they are the experts and that you need their help to understand the business.
These interviews will help you understand why the decision was taken to prepare a financial model. They should cover the history of the company, including key policy decisions that have been taken and their impact on the company's results. You will need to make an assessment of key management personnel and the extent to which you can place reliance on their assertions. You will need to document your discussions as thoroughly as possible...