just a quick tip: if you are able to, try shipping thru Paypal. you will always have a tracking number, no matter how big or small the package. it is not an additional charge. it is also cheaper! I've shipped A LOT for a small business and here on Listia, and Paypal really saved my butt a lot :)
if you don't already have one, create a paypal account. then go to paypal dot com / shipnow. you will need a kitchen scale so you can weigh items but that's pretty much it! enter the buyer's Listia verified address, select how you want to ship (First Class is cheapest, 0-13oz) pay & print! the tracking # is at the bottom of the label & will be saved on your paypal acct as well, if I remember correctly. hope that helps!