I've seen many people confused by Vim's help system, particularly when installing a new plugin. An IRC friend of mine had installed Tim Pope's rails.vim, and couldn't work out why
:help rails didn't work. The reason for this is Vim has to be told about new help files through the
Vim itself has documentation for
:help :helptags, and the command can be abbreviated to
:helpt. Running it with the directory your plugin was installed to will make the help file available.
Let's say you've installed rails.vim to
~/.vim/bundle/vim-rails because you use Pathogen, then to generate the help tags you'd have to type
However, realising that generating help tags is often a chore, Pathogen includes a
:Helptags command that automatically generates help tags for every directory in
runtimepath. Also, Vundle automatically generates help tags for the plugins it manages.
If you're used to other editors, then having to run a command to make plugin help files available might seem a bit strange at first, but it's just one of those things you need to be aware of when using Vim.
runtimepath, I'll explain more about that in a future Vim 101 post.