You just need 3 things ready before you start the sign-up process for AdSense account,
1. A Google account.
2. Content created from scratch.
3. Phone number and postal address.
The Step by step sign up process
1. Click Sign up now.
2. Enter the URL of the site that you want to show ads on.
3. Enter your email address.
4. Choose whether you'd like AdSense to send you customized help and performance suggestions.
5. Click Save and continue.
6. Sign in to your Google Account.
7. Select your country or territory.
8. Review and accept the AdSense Terms and Conditions.
9. Click Create account.
10. You’re now signed in to your new AdSense account.