Debian GNU/Linux is distributed freely over the Internet. If you simply want to install Debian, these are your options:
Buy a set of CDs
The easiest way to install Debian is with a set of CDs bought from a vendor. There are a number of places you can obtain these CDs, such as:
Download files over the Internet and make a CD set yourself
The biggest advantage of downloading the .iso files and burning them yourself is not having to wait for CDs to arrive. The full 14 CD set can be downloaded in .iso format from [http://www.debian.org/CD/http-ftp/ one of the Debian mirrors], or better yet, using the [http://www.debian.org/CD/jigdo-cd/ jigdo] tool to do a distributed download of the images.
Note only the first CD is required to install debian. The extra CDs are optional and include extra packages.
If you do want to download one or more of the full 650 MB iso images, please use the [WWW] jigdo tool which spreads out the load among various Debian servers, lightening their load as well as giving you a faster download.
Download the Network Install CD
For folks with broadband internet access, it's quite rare to download a full set of 650 MB iso images to install Debian. Instead, it's most common to just use a minimal network install CD instead. This network install iso (called "netinst") contains just enough packages to install a very basic Debian system. During the install procedure, it downloads the rest from the Internet as needed. A netinst iso image is around 180 MB. Also available is the so-called "businesscard" image that is around 40 MB. [http:DebianNetworkInstall read more: ]
There is also the possibility to boot from another computer without needing to use CD/floppy media at all. All you need is a TFTPD and a DHCPD running on the install-from computer. This is called installing via "netboot". See the installation manual for more info on netboot installation.
[http://www.well.com/~allyn/debian_d945.html Install Debian on Intel D945]
[http://www.well.com/~allyn/debian_ati_sb450.html Install Debian on ATI SB450]
[http://www.well.com/~allyn/debian_d915gm.html Install Debian on Intel 915GM Mobile Platform]