To sign up for Yahoo!Yahoo!'s personalized services, just follow the instructions for new users on the sign-in page of any of Yahoo! personalized services.

If you have not created a Yahoo! IDYahoo! ID click on “Sign In” then “Sign Up”

During registration, you'll be asked to choose a Yahoo! ID and pick a password. Please Note: Your Yahoo! ID cannot contain special characters or spaces. After you've signed up, you can use this same ID and password for all of Yahoo!'s services.