There is a free program from the Post Office called "Click-N-Ship for Business"

 You can use it to printing labels for shipping and customs forms.

When you ship using it, even if you don't pay until you get tho the Post Office, Tracking is free for First Class and only 23 cents for Media.

I just print out the labels and go to the Post Office and they scan the bar code and pay them and the tracking is always free or 23 cents.

I do it this way because I like my postal workers and want them to be needed.

I have an old scale for weighing food that I use and it is always correct on the shipping weight.

The program keeps track of all my shipment and even allows me to check the tracking on a package to find out where it is while enroute.