Vim: Possible to make default split vertical when opening help or file instead of horizontal?

Solution 1:

Vim provides these commands:

:vert[ical] {cmd}
    Execute {cmd}.  If it contains a command that splits a window,
    it will be split vertically.

:[count]winc[md] {arg}
    Like executing CTRL-W [count] {arg}.

Therefore:

• To open a vertical help window type :vert help
• To edit the file name under cursor in a new vertical split type :vert winc f

Solution 2:

This moves the help window once. So you can freely move it around after the window is created.

if has('autocmd')
  function! ILikeHelpToTheRight()
    if !exists('w:help_is_moved') || w:help_is_moved != "right"
      wincmd L
      let w:help_is_moved = "right"
    endif
  endfunction

  augroup HelpPages
    autocmd FileType help nested call ILikeHelpToTheRight()
  augroup END
endif

The function, ILikeHelpToTheRight() will only run wincmd L once per window (it's what the w: prefix is for).