The Debian System was created in 2005.
Debian was created on 1993-08-16.
It was originally created to be a temporary fork of Debian to allow for the development of strong desktop features for it. In the end, however, Ubuntu stayed forked and Debian doesn't generally benefit from Ubuntu's feature set. Short answer: Ubuntu was created to produce a "user friendly" version of Debian.
Ian Murdock created the Debian distribution. The name of the distribution comes from his own name and his wife's (DEB-IAN).
Debian is a free Linux distro. It focuses on stability and freedom (as in speech) of software. Debian is distinguished by it's excellent package management system. If you want a solid and stable server, Debian is an excellent choice. If you need more cuting-edge software (the stable versions of Debian are sometimes made fun of for having really old versions of programs), try a distro based on Debian, such as Ubuntu or Sidux.
All Debian ISOs are "full-featured"; you can use any of them to install any Debian programs. The KDE and GNOME ISOs are probably best if you want a desktop system, and the netinstall is a better solution for servers and systems you need / want to customize heavily. However, nothing stops you from, say, installing KDE on the netinstall system, or installing Apache on the GTK system.
Simple. You just download an ISO image off of Debian's website, burn it to a CD, and boot your computer from it. All versions of Debian are "full-featured", though the Minimal CD can be used to install only a base system and whatever additional packages you want.
DEB packages are packages made for Debian and Debian-based distributions.
This is dependent on the package management system. Debian has Synaptic.
Yes. Debian can be downloaded off of its website free of charge. Alternatively, you can purchase a copy of Debian for a very small fee from numerous online vendors.
Debian 5.0 (Lenny) debuted with the 2.6.26 kernel.
One can find information about Debian dedicated servers by going to the Debian website. The website has information and support services about their servers.
Historically installing Debian has not been a very user friendly process. There are automated installers now but it can still be a fiddly job. The easiest way is probably to use Virtual Box (See links below). If it does not have to Debian itself then Ubuntu is probably a neater solution and is itself based on Debian. But if you are running Mac OS X you already have a full UNIX system so may not need a pretend one.