About reconciling your accounts (an overview)
Some things you may want to consider before you begin your reconciliation:
If this is your first time reconciling this account, make sure you've added all your transactions and your opening balance is correct.
If your beginning balance is different from the balance on your current paper statement, you may need to track down the discrepancy before you reconcile. Click Locate Discrepancies in the Reconcile window to find out how to do this by viewing different types of reports.
Begin your reconciliation
To do this task
Choose Banking > Reconcile to open the Begin Reconciliation window.
In the Account field, enter or select the account you want to reconcile.
In the Statement Date field, enter the date of the bank statement you are trying to reconcile.
Compare the amount shown in the Beginning Balance field to the opening balance amount shown on your statement.
Find the ending balance on your statement and enter it in the Ending Balance field.
Enter any service charges or interest earned that you have not already accounted for in QuickBooks.
If the financial statement shows a service charge or interest that you haven't yet entered into your QuickBooks records, enter those amounts into the Service Charge and Interest Earned fields.
Important: Don't enter charges you have already entered as QuickBooks transactions.
In the Account field for service charges, enter the name of the expense account that you use to track service charges. In the Account field for interest, enter the name of the income account that you use to track interest income.
Click Continue to open the Reconcile window for the account you've chosen.
Finally, complete your reconciliation.
(I copied this direct from my QuickBooks, I hope it helps)