Now of course you need to know WHEN your order will ship and from WHERE. I generally ship the day following the placement of an order.
Here is the USPS postage and ETA calculator - remember that at Christmas time it might take the postal people an extra day or even two to get the high volume of packages delivered.
Below are a few visuals to help you out (click on the pics to enlarge)... In this example I will ship a package to zip code 89509 in Reno, Nevada on December 17th. Since I'm shipping everything Priority after the 17th, the post office is indicating an ETA is the 19th. That seems a little fast for the Christmas rush doesn't it? I'll see how long it takes by the delivery confirmation. So far all of my shipments have arrived earlier, on time or within 1 day after the ETA shown using this calculator. My post office system is terrific here in Detroit; remote areas experience delays though.
After you click "continue", you'll get a new screen with shipping options and prices. I circled the ones I use the most.