IS-Media: How to upload Business partner values

Hi,

My client is into IS-Media. I have a situation where I need to upload Business partner values.

Please correct me if I am wrong:

1. Each BP has assigned with ONE contract account.

2. If I upload values to CONTRACT account, will that be enough.

3. What is the best way to upload values in contract account. I assume, if we upload values to contract account in turn it will be available for that BP.

4. Kindly let me know the best way with step by step.

Thanks in advance.