OK so I am just messing around with cafe press for the first time today. I read the instructions on the best way to create your design but I have one question that is probably simple. I just need confirmation that I am doing it right. I am using the templates. My designs are simple phrases. So once I type them in the center of the template am I supposed to crop it all the way down to eliminate the white space? I am not actually inserting any white so when I upload my design how is it actually going to print? If I leave it the template size with text in the center am I going to have a white box printed on my design even if I am using white t-shirts?

The template represent the printable area of the shirt. While you are allowed to crop it that doesn't make it the best practice. If you want the text to cover less than the printable area it is best to leave it on the template. That will retain the proper relative size. If you crop it then it will be applied as big as the available resolution allows. (See http://tutortanith.com to understand image sizing).

Hopefully you are working with a graphics application that supports layers so that you can remove the actual template part by deleting that layer. That will, ideally, leave you with text on a transparent background. White backgrounds will print as a big white block on dark apparel, but will not print as white on light apparel. On light apparel white=transparent. On dark apparel white=white.