Documents related to ALE & EDI

Hello Everyone,

Can anyone provide me the good document regarding ALE & EDI, which gives me the flow about:

1. How Idoc is created (after triggering through any Transaction or using Program - With & whout Message Control)?

2. Then, how it is passed to another partner in case of EDI and ALE?

I want a flow in detail, so that I can work on it.

Thanks in advance.

Please help ASAP.

Kind Regards,

Prasad