Speaking of RubyGems, I did as you said using the
  sudo apt-get install libyaml-ruby1.8 libzlib-ruby1.8 and everything
seemed to be operating correctly.

The apt-get process stated selecting libruby1.8 instead of
libyaml-ruby1.8 and selecting libruby1.8 instead of libzlib-ruby1.8 but
ended saying 0 upgraded, 0 newly installed, 0 to remove and 0 not
upgraded.

Then I tried the setup as follows:
@ubuntu:~/MyDocuments/Downloads/gem/rubygems-0.8.11$ ruby setup.rb
---> bin
<--- bin
---> lib
---> lib/rubygems
<--- lib/rubygems
<--- lib
---> bin
<--- bin
---> lib
---> lib/rubygems
<--- lib/rubygems
<--- lib
rm -f InstalledFiles
---> bin
mkdir -p /usr/bin/
install gemwhich /usr/bin/
setup.rb:513:in `initialize': Permission denied - /usr/bin/gemwhich
(Errno::EACCES)
        from setup.rb:513:in `install'
        from setup.rb:1193:in `install_files'
        from setup.rb:1192:in `each'
        from setup.rb:1192:in `install_files'
        from setup.rb:1172:in `install_dir_bin'
        from setup.rb:1321:in `traverse'
        from setup.rb:1319:in `dive_into'
        from setup.rb:1319:in `traverse'
        from setup.rb:1313:in `exec_task_traverse'
        from setup.rb:1308:in `each'
        from setup.rb:1308:in `exec_task_traverse'
        from setup.rb:1168:in `exec_install'
        from setup.rb:887:in `exec_install'
        from setup.rb:705:in `invoke'
        from setup.rb:674:in `invoke'
        from setup.rb:1352

A couple of times I got permission denied, but I am the sole owner of
my computer.

It looks like RubyGems might be installed, but if so, not in the right
directory or possibly not in the path?

Anyway I still get file not found after I type gem at the command line.

Hope this is not too much for you. Any help would be greatly
appreciated. I am dying to get at the applications programming, but
this is killing me!

Thanks,
Les