so im working with Photoshop CS3 Extended (cracked n pirated), and i made a render with a ton of white space. How do i cut the white space out so that it becomes an empty/transparent pixel?

the cut tool Forgot the Name of it or the pen tool

if i read correctly, u can just create a new document and set its background as transparent..?

Or you can hide the background (The bottom layer on the right) - To easily recognize the background, it's Lock - You need to double click it to unlock it. But You can simply hide it and you'll see some grey/white square - it mean the bg is transparent. Just save it as .png now - it'll work flawlessly.

start by opening your picture you want to cut. cut it with the polygonal lasso tool (right click on lasso tool & select 2nd)
cut around the edges & don't let it go untill you meet your start. i.e start one position & end same position.
ctrl-c & open a new document. under the pixels & such set the background to TRANSPARENT & copy it over there.