Here are some helpful tips based on popular services used for shipping books/music.
Media Mail- ONLY for shipping books and media (CD's). Media mail is low in price, but can be slow in delivering the product. Price does vary based on zip code and weight. You estimate the price at about $2.77 with your own envelope. The website is not setup to change the shipping price based on USPS rates so if you want to use this method, you will need to estimate the price for the shipping method in your admin. I recommend using a padded envelope and purchasing tracking with it. The padded envelope helps prevent damaged products and tracking helps confirm package arrived to the destination. Tracking is an extra feature and is usually around $.90 so make sure to add that in your shipping price. The tracking number will be printed on the receipt, so SAVE YOUR RECEIPTS!
First Class- this service can be used for anything, but since we are only targeting books we will stay on that specific subject. You can use your own envelope. If you are using an envelope, one book is the maximum you can ship because of the weight restrictions (up to 13 oz.). The estimated time of delivery and price depends on the zip code but from my experience shipping all over the U.S. it takes approximately 2-3 days. Ask the clerk to give you prices for First Class vs. Media Mail. Compare the prices as well as the delivery times- Sometimes you can pay media mail price but still get a fairly fast delivery time. Don't be shy, just ask! And, don't forget to ask for tracking!!
Priority- this service has several options, but I am only going to list three of the most popular.
Priority Mail 2-day small envelope- this service is based on your own envelope(of course you can always buy them at the Post Office for an arm and maybe a leg if you really needed to). It can hold about 3 books (4 will be very tight but can fit). It is based on zip code and weight. The estimated price for this service is about $6.95 and includes $50 insurance and tracking.
Priority Flat Rate small envelope- this service has a FREE (can you believe something is FREE?) envelope and has a fixed price so it does not matter where it is going in the U.S. it is only $5.60. It can hold about 3 books (4 will be very tight but can fit). This option usually takes 2 days to get to the destination and also includes $50 insurance and tracking! I recommend this option if you are wanting the book/music to arrive in a short amount of time and not pay a fortune.
Priority Flat Rate medium box- this is a lot bigger than the envelopes and obviously can hold more items. You can fit about 4-16 books in the medium size box. This also is 2 day delivery and includes $50 insurance and tracking.