http://www-128.ibm.com/developerworks/linux/

IBM Linux portal

http://www.captain.at/howto-linux-boot-cd.php

This howto uses isolinux to boot the cd, not like other boot CD's, which use "El Torito". Booting a CD via "El Torito" uses a disk image similar like a floppy image, which will take care of loading and configuring the system and the rest of the CD.
Booting a CD with isolinux is pretty straight forward. Isolinux will load the kernel and the initial ram disk (initrd) - the ramdisk (with linuxrc) will take care of mounting the CDROM and doing further initialization.

The scripts:

• check.sh will check if all needed binaries and libraries are available on your base system. If something critical is missing, i.e. a library, replace the name of the library with the new name (most likely only the version number will have changed). Don't forget to update the symlink name aswell (if it has changed at all).
• make.sh will create the directory structure, copy binaries, libraries and configuration files.
• iso.sh will create the initial ramdisk (initrd), the root filesystem (rootfs) and the ISO CDROM image itself.

http://www-128.ibm.com/developerworks/linux/library/l-fireboot.html?ca=dgr-lnxmvp15fireboot

Say you want to use Linux in a dual-boot arrangement, but you don't have any free space on your computer's hard drive. One solution would be to use a "live" Linux distribution such as Knoppix, which can be run directly from CD. This is certainly viable for occasional use, but it has a number of serious drawbacks:

http://www.tldp.org/HOWTO/Bootdisk-HOWTO/buildroot.html

Creating the root filesystem involves selecting files necessary for the system to run. In this section we describe how to build a compressed root filesystem. A less common option is to build an uncompressed filesystem on a diskette that is directly mounted as root; this alternative is described in Section 9.1.

http://www-128.ibm.com/developerworks/linux/library/l-initrd.html

The initial RAM disk was originally created to support bridging the kernel to the ultimate root file system through a transient root file system. The initrd is also useful as a non-persistent root file system mounted in a RAM disk for embedded Linux systems.

http://www-128.ibm.com/developerworks/linux/library/l-linuxboot/

Linux boot up