To sign in to the Yahoo! homepage:

1. Move your mouse cursor over Sign In at the top of the Yahoo! homepage.
2. Click Yahoo! or Facebook.
3. Enter your login credentials.
   For Yahoo!: Your Yahoo! ID and password.
   For Facebook: Your Facebook login and password.
4. Click Sign In.

If “Sign Out” appears at the top of the Yahoo! homepage, then you are already signed in to the Yahoo! homepage with either a Yahoo! ID or Facebook account in your browser. You could be signed in through Yahoo! Mail, My Yahoo!, or any number of other Yahoo! properties.

If you don't have a Yahoo! ID, you can sign up here.

To learn more about the features available to you after signing in to the Yahoo! homepage, see the benefits of signing in to the Yahoo! homepage.