There are two ways to make tables of contents in Word:

1. Create them manually, update them manually, hate life
2. Do everything automatically

Unless you're interested in doing a lot more work, choice 2 is better for you.

First, you must use styles to create all of your headings, not manually-applied formatting. Using styles will make your life easier anyway, fewer actions to get the formatting you want.

Then, select Insert > Reference > Index and Tables.

If you're using the built-in styles, or have created your own styles by changing the attributes (but not the names) of these styles, go ahead and click "OK". If you're using your own manually-defined styles, click "Options" and tell the program at which level each of the styles you're using is.

If you want to control the output style, click "Modify" and change the text styles used.

If you want to change how Word separates your page titles and numbers, change the tab leader.

Hit OK to create.

Wasn't that much easier than doing it all by hand? Plus, when you right-click and select "Update", the TOC will automatically update. Now that's time-saving!