This is confused by the number of different distributions available. Read the Debian installation read-me file. Locate a Debian distribution CD-ROM or other distribution. If necessary, prepare a bootable floppy disk. Understand hard disk partitioning.
Failures here are difficult to recover from.
Have all necessary file to boot the system on the root partition. Have twice as much swap space as real memory. Place the swap space on the least busy fastest device. Place a swap partition near the center of the disk. If a daemon logs too much, it should not prevent a user from saving its work.