Muhammad,
You are in the unevnviable position of not knowing the product but yet leading the implementation of it. You will have to rely on your partner heavily for advice and guidance.
However, my advice to you as project manager is threefold - 1. Make absolutely certain that the external implementation team understands your business processes thoroughly prior to configuring the software, 2. prepare your internal team (implementation and end users) for the upcoming changes in the way data is processed, and 3. do not skimp on training!
Number 1 is important because you want to be able to leverage the capabilities of the software and keep customizations to a minimum. Number 2 is important because the way people do things will change. This is true with any ERP implementation. Do not let users try to fit the software to existing business processes because 'that's the way we've always done it'. This also is important to keep customizations to a minimum. Number 3 is important because people need to know ALL the features of the software that are designed to make their jobs more efficient and effective.
As you might imagine, these are the 3 areas I see over and over again that are not adhered to strictly in ERP implementations but which have a major impact on the ultimate success of the project.
Good luck and let us know how it goes. Oh, and welcome to the forum!