How to print Shipping Label in Magento
Go to admin-> topmenu-> sales-> order-> order list
Then you can see the list of orders, click on a order to view it.
In the order details page you can see "shipment" tab in the left, click on it then you can see the created shipment like the following PIC.
Now click on the shipment. Then you can see the shipment details. In shipment details page you can see "Download shipping Label" in the "Shipping and Tracking Information" section like the following PIC.
Click on the "Download shipping Label" button, then you will be redirected to a PDF page in new tab in you browser. Now click on the print button on the pdf to print it.