Adding new pages
The 'Define New' button > SEO Title, Meta Descriptions, etc.
You can find these fields by clicking the 'Define New' button for a new page, or the 'Define' button for an existing page.
These fields are for SEO titles, meta keywords, and meta descriptions unique to the particular page you're working on. For site-wide meta tags, such as browser verification meta tags, see the Analytics help page.
Add an SEO title for your page. This is what displays at the top of the browser window when someone views your page on the web. This is a very important feature for search engines. It is an opportunity to briefly tell the search engines what can be found on that page. Try to keep this title under 60 characters or so, since this is the text that shows as the link to your site in peoples' search engine results pages. If you make the title too long it will get truncated and you can't control where it will get cut off at.
Same concept for the Meta Key Phrases and Meta Key Words boxes. Come up with 5-10 keywords or phrases, comma separated, that describe the content of this page. These words and phrases must be somewhere in the page to make a difference. Google doesn't use keywords in their search algorythms anymore because of abuse of this meta tag; people stuffing it with keywords that will get search engines to find their page, but that did not describe the content of the page at all. They rightfully call that keyword stuffing. Don't neglect this box though as there are still search engines out there that use this meta tag. Just make sure your key words describe the content of the page, not your website in general.
Don't use this Analytic Code box at all, unless you are tracking particular pages of your site separately in a second analytic account. Use the Analytic Code tab to put your analytic code on every page site-wide.