:help messages gives the list of various vim messages as :help :messages
points to the correct documentation section.
    
        | author | Yann Thomas-Gerard <inside@gmail.com> | 
    
        | date | Thu, 06 Jun 2013 16:13:35 +0200 | 
    
    
        | parents | 56683eb09ecc | 
    
        | children | c83035f5644b | 
    
        | branches/tags | (none) | 
    
        | files | chapters/01.markdown | 
Changes
    
--- a/chapters/01.markdown	Thu Apr 04 01:38:14 2013 -0400
+++ b/chapters/01.markdown	Thu Jun 06 16:13:35 2013 +0200
@@ -60,7 +60,7 @@
 
 Read `:help echom`.
 
-Read `:help messages`.
+Read `:help :messages`.
 
 Add a line to your `~/.vimrc` file that displays a friendly ASCII-art cat
 (`>^.^<`) whenever you open Vim.