Always name your main page: "index.html"

Do not use spaces in file names:   ex.  bad->   1st year course.html
                                                        good->   1styearcourse.html or 1st_year_course.html

When working with a program (Nvu Mozilla/ Dreamweaver) to help you write your page(s) check the help tab at the top if experiencing difficulties.

Use tables for spacing and layout as opposed to spaces and tabs.