You can download map files to import your invoices or bill transactions from CommonSku
to be used with Transaction Pro Importer ("TPI") for QuickBooks here
. Save these files to your local machine and when you get to the TPI mapping screen select the load map button at the bottom of the screen and navigate to where you saved these files.
On the first screen of TPI be sure to select a delimited of comma from the drop down in the middle of the screen. Also select the proper import type: bills or invoices.
Also here are some more detailed articles for you to review:
How to import bills
How to import invoices