I opened the Vim user manual with the :h user-manual | only
command (to open it in one window) and now I want to enter/open the separate text files. I tried to put my cursor over a section, such as |usr_01.txt| , and press CTRL-j but nothing happened.
Overview ~
Getting Started
|usr_01.txt| About the manuals
|usr_02.txt| The first steps in Vim
|usr_03.txt| Moving around
|usr_04.txt| Making small changes
|usr_05.txt| Set your settings
|usr_06.txt| Using syntax highlighting
|usr_07.txt| Editing more than one file
|usr_08.txt| Splitting windows
Best Answer
To navigate to the section under the cursor, you use Ctrl] (that's a right bracket, not a j):
http://vimdoc.sourceforge.net/vimum.html