B1 Newbie - Need Help

Hi all,

I'm new to SAP and need to write an app that exchanges data with SAP B1 - Its going to be between a Point of Sale app and SAP

The Problem is that I dont know were to start(with SAP).

Has anyone written a point of sale or similar using SAP?

I Have many questions, here are a few - My app will import data sent from the POS app - the data will be transactions eg Sales,Payments etc... How would I import this into SAP?

What Tables would I use?

All suggestions,advice,help welcome.

Thanks