When you're done, you can click on the 'Close' tab on the floating bar. The items in the header and footer will appear greyed out, but don't worry; this only means the they have been set. The cursor will then appear on the first line where you can begin typing your letter.
Moreover, you can also use Word templates for letterheads, invoices and even for monthly business reports. This is because it is integrated with other Microsoft Office programs such as excel. This way, you can import graphs and other objects necessary for completing a well formatted report. There really is a long list of uses for Microsoft Word. You will certainly find it useful whether you are a student, a professor, a businessman, a home maker or whoever you are from whatever industry.