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