Basic Questions on ARM

Hello,

I am new to ARM and have the following basic questions:

1.  When you load data to ARM, do you keep the GL balance natural sign, i.e. assets are positive and liabilities and equity are negative?

2.  How does the 'Source System Beginning Balance' field gets populated?  Is this the ending balance from piror period, obtained from copying the reconciliation to the current period?

3.  What about the 'Net activity' field?  What does it represents?

Thanks.