Management reporting for voluntary organisation

A voluntary organisation in NZ has contacted me for assistance with preparing consolidated management reports (ie actual/budget, P&L & B/Sheet) for all its branches.

Aside from immediately obvious things (at least to me), such as one accounting system, common chart of accounts, common departmental structure), can anyone suggest any practical tips to help get this job done?

The majority of branches are currently using MYOB. Everything else (budgets, all existing reports) are being done in Excel.

I'm interested to find out what systems and processes are of practical benefit in this scenario.

REgards
Mike

PS I've ticked this question as being of student interest, because it doesn't fit any other category, but anyne can reply!
Mike James