Network install without floppy/CD
 

I want to try Debian.
I don't have a floppy drive, and have no empty CDs. I want to do a network-install.

Which files do I need?
I've read the installation guide, but there's simply too much information there so I cannot find what's important for me. (I have an existing Linux installation which I can use to download the necessary files)

My hardware:
CPU: AMD Duron 2800+
Gfx: ATI Radeon9800Pro
MB: Asus A7N8X-X (nforce 2)
RAM: 512 MB DDR
HD: 40GB + 120GB
DVD: NEC 2510 (16x DVD writer)