The print queue is useful for printing checks at a later time. You can enable check printing in Settings -> Company Information.
With check printing enabled, any time you pay a vendor bill or an owner draw with Check as the payment method you will be prompted to print that check. You can select Add to Print Queue if you do not wish to print it right away.
Once you add a check to the print queue a notification will be created in the notification center. There you can click on it to open the print queue.
In the print queue you can select which check to print (you can only select one at a time) by clicking the checkbox on the left.
You can also remove it from the print queue by click the X on the far right.
Then you can hit Print at the bottom and it will bring up the normal print preview menu for you to print or download the PDF. You can then return to the print queue to print the rest of your checks.