1). If there are any new accounts opened than need to added them in Metadata Account Structure.
2). Opening the period for that month.
3). Loading the data for the Accounts.
4). Entering the Exchange rates if its an International Business for that month.
5). Entering the Historical rates for that month.
6). Running consolidation for that month for all the Entity Structure of the business.
7). And finally validating the reports like Profit and Loss, Balance Sheet.
8). And after all the process is done than lock the periods for that month so that no data will be modified.
These are the most general activities which will be performed in an month closing, hope this would help you.