How to load external data to SAP BW?

Hi All,

I try to load data from external application to SAP ware house using RFC, as i am new to SAP BW, I would like describe my question as below.

1. I have run RFC server in my local machine and resister in the SAP system successfully.

2. In the source system, i click check, connection OK.

3. Create DataSource in the Data Sources.

4. Create InfoSources, it contain two rows. but when i try to create transformation, it always give the message "Source doese not exists".

I am not sure why this happened, could you please give some advices. Besides, where can i get some tutorial document of this operation on SDN?

Thanks.