The docs show the syntax and code fragments, not entire compilable examples. Although if you provide a main() and copy the code, with some slight adjustments it should work. In cases where it's obvious that a code sample would not compile due to some typo or mistake, you can file a bug report.
If there's missing documentation, file a bug report. Otherwise the docs are not a tutorial for the language. If there ever will be a tutorial that's hosted on the D website it will probably be in a section of its own. Foo/Bar are typical ways of naming symbols in example code. See http://en.wikipedia.org/wiki/Foobar . I'm not sure what you mean by lack of organization. Although maybe adding a "Jump to" section on the top of each page could help figure out what is listed on each page.