To insert page numbers go to the first page of the document.

Click on the Insert tab
Click on Page Number

A menu will appear with options for where you want the page number to be inserted.

You have the choice of placing the number at the top, bottom, page margins or current position of the page.

When you click the black triangle to the right of your choice, you have a further choice of exactly where in that top or bottom of the page you want the numbering to appear.

Headers and Footers

Headers appear at the top of every page, outside of the normal printing area of the page. A header, once created, will appear on every page of the document.

On the Insert tab, click on Header. You will be presented with a choice on how you want the Header to appear.

Footers appear at the bottom of every page, outside of the normal printing area of the page. A footer, once created, will appear on every page of the document.

On the Insert tab, click on Footer. You will be presented with a choice on how you want the Footer to appear.

You will see a dashed line outlining the area of the header at the top of the page and a similar area outlining the footer at the bottom of the page. A toolbar also appears on the screen (experiment with this yourself). These areas outlined with the dashed line are like little pages and you can write in them and insert graphics as is it is a normal page. Normally one does not put more than two lines of information in a header or footer.

Once you have completed the header / footer, click on Close in the Design tab.