The manual should be clear and concise. It should be spell- and
grammar-checked.
There should be a "credits" section at the beginning which
indicates whether any outside resources were used (such as
information or code from other webpages, textbooks) and also
which team member contributed to which aspects of the project.
The first page should contain some general information
on the purpose, features and limits of the software.
The next two pages should be "help pages" for the user. These should
not be written like an essay but instead should have some
structures (headings, lists, FAQ) that make it possible to find information
quickly. But there needs to be
a good balance: too many headings, lists, etc may make it as difficult
to find things as too few.
The instructions should be not too detailed (such as "open your browser,
scroll down to ...,") nor too general.