The Story
I decided that it is finally time for me to stop just putting .rb
files on my own server, and instead start hosting them as gems.
(Mostly because I now have one library that relies on another, and I
need them installed in some common spot for require to work cleanly.)

So, last night I googled "rubygems create gem gemspec" and the second
hit was:
http://rubygems.org/read/chapter/5
which says "This is a skimpy overview; see the DeveloperGuide for the
real meat."

But I couldn't figure out what the DeveloperGuide is, so I googled
"rubygems DeveloperGuide wiki", and the first hit was:
http://osdir.com/ml/lang.ruby.gems.devel/2006-06/msg00044.html
...
which is a post from 1.5 years ago by Jim Weirich saying:
"The wiki is totally decommissioned.  I should see if there is a way
for Tom to disable it."

OK, so apparently I was looking at bad data. That's not uncommon. I
decided to start at the source. I go to rubygems.org and...well, you
can go there and see that it has a link to the same documentation I
was seeing previously.

I googled for "DeveloperGuide site:rubygems.org" and found 5 hits that
all refered to the absent DeveloperGuide.

I look around on the rubygems.org site in the other documentation. The
FAQ surprisingly (to me) doesn't have an entry on how to create a
gemspec. The gemspec reference is a reference, about as useful for
creating a gemspec as a dictionary is useful for learning how to write
an English paper.

The Request
Help! How do I create a gem? I know that once I do, and upload it to
rubyforge, that it will magically be available to all. But first I
need to create one, and...I'm stumped.

The Request II
Hey rubygems developers, please put up a simple HOWTO that walks
someone through the basics of creating their first gem. Preferably,
put it in prominent locations on your website, in the places where
Google is bound to land. Please, clean up the documentation to remove
references to DeveloperGuide, or hotlink the existing link to
something useful.