This chapter explains how to write an Info file by hand. However, in most cases, writing a Texinfo file is better, since you can use it to make a printed manual or produce other formats, such as HTML and DocBook, as well as for generating Info files.
makeinfo command converts a Texinfo file into an Info file;
texinfo-format-buffer are GNU
Emacs functions that do the same.
See Overview of Texinfo, for how to write a Texinfo file.
See Creating an Info File, for how to create an Info file from a Texinfo file.
See Installing an Info File, for how to install an Info file after you have created one.
However, if you want to edit an Info file manually and install it manually, here is how.