Meta tags are bits of HTML code that provide information about your page, which help search engines classify and rank your site. You can specify the title, description, and keywords for each of your pages in the Enter Meta Tags dialog.
Title:
Page titles are displayed in browser title bars and bookmark (or "favorites") lists. More importantly, search engines use titles to index web sites, and often display them in search engine results.
Give some thought to choosing a concise, descriptive title for each page of your web site, making sure it includes one or two keywords that appear on the corresponding page.
Description:
Your description summarizes your page's content. Some search engines use this description to help categorize your page, and a few even display it in search results!
With this in mind, try to make your description both readable and interesting, featuring one or two keywords that appear in your content. (Having trouble thinking of a description? Try using the first sentence or two from your page.)
Keywords:
Though the keywords tag isn't as important as it once was, effective keywords can still influence your search engine rankings.
Enter your keywords in order of importance, and be sure to use keywords that actually appear in your page content. Don't repeat keywords more than twice (and not consecutively!), and keep the list under 256 characters. Learn more about choosing keywords.

Author:
You can easily add an author name (generally your own name or the name of your business) to any of your pages in the Page Properties tool. However, most search engines don't support the author tag, so you may skip it, if you like.