Click the "Add New Website" link in the upper left dropdown menu.
Then click the "Add a single site" option. Fill out that form, and you'll be redirected to the keywords page:
Add the keywords you'd like to track
All done! Happy keyword tracking
Now your keywords will update daily, and any pages we find that rank in the top ~120 of Google will be imported into your account so that you can view at the page level as well:You will only see rankings data on the page level view, but you can at least see Google and Yahoo rankings over time!