Regarding Windows NT

Windows NT installation CD is by itself bootable, if you have genuine licensed version, hence you need not install any other previous OS. But why are you installing Windows NT. You will not get any support from Microsoft if you have any problem as they have stopped support of the same. They not releasing patches for any new vulnerabilities discovered, hence your system will vulnerable to attacks. Go for either Windows 2000, XP or 2003 which are still supported.
Best of Luck

you will be installing nt beginning by floppy then progressing to the installation cd. are you asking how to install nt if you have no floppy drive?
to try to answer your questions:
1. if your nt is an upgrade, you don't need to have the upgradable version installed on your hard drive but you will need to produce a windows 98 installation cd for example, to 'show' proof of ownership to the setup program
2. most cd burning software has a way to make a bootable cd. it makes a cd that the system thinks is a floppy. i don't know of a free utility for doing this...

Your machine must be able to read a bootable cd. (Your NT installation) this explains that aspect.

http://support.microsoft.com/kb/q167685/

Alternativly you can have a standard dos partion, boot to it load your cdrom driver to access the cd drive in dos.

Then on the cd drive in the I386 directory you install with the WINNT.EXE (For dos) or the WINNT32.EXE (For windows)