Concept wise Presentation in SAP..guide for freshers.

Hi Guru,,.

Good evening to all .

I m freshsers in SAP-MM, right now i m working in post implementation site.first they told me give a presentation in SAP-as is (completed). Now they telling to give me a concept wise presentstion in SAP.

first of all what i want to prepare , i m not any idea.. please guide me anybody. In which way i want prepare all the things in SAP-MM.

And also please tell me how can i learn more in post implementation site. what are all the things are there in post implementation site to learn as a SAP freshers.

Thanks

sap-mm