Here is a list of KB articles I reference.  I have these bookmarked and have found them to be extremely useful.

General:
Microsoft Dynamic GP Directory – Quickest way to locate updates and year end information
888003 – Year-end closing procedures for General Ledger
864652 – The checkbook balance and the general ledger cash account do not balance

Bank Reconciliation
872693 – Description of Bank Reconciliation tables
851301 – Error message when you reconcile the checkbook in Select Bank Transactions in Microsoft Dynamics GP: “The difference must be zero before you can reconcile this checkbook”
857211 – How to start using an existing checkbook to reconcile in Bank Reconciliation
866167 – Description of the transaction flow in Bank Reconciliation

Electronic Bank Reconciliation
2872105 – Steps to modify the BAI file format in Electronic Reconcile
850751 – Setup information for Electronic Reconcile Format Configuration

Payables:
858279 – Payment Date on the Payables Historical Aged Trial Balance
936280 – Return transaction document types

New GP Company:
866332 – Copying chart of accounts from one company to another using Microsoft SQL Server
872709 -How to copy setup tables from one company to another