Whenever you want to sign into a web site or service, look for the Sign In link (usually at the top of the page) and click on it.

Netscape or Internet Explorer users only: If you have not yet signed in with your screen name and password, you will need to do so first.

You may be prompted to confirm that you want to sign into that web site. If you wish to avoid that confirmation in the future, simply tick the Don't show me the page again tick box on the page. When you sign into a site, the site receives your screen name so that it can remember you while you are using that site. Once you are finished browsing the web, click Sign Out to sign out of all the places you visited using the Screen Name Service.