Assuming that you have already created a GMail Account:
STEP 1. Open your internet browser, type google.com/adsense in your address bar and press enter.
STEP 2. Click "Sign up now" button
STEP 3. You will be asked to enter details such as:
Website URL:
Website Language:
(Tick 2 Check Boxes)
Account Type: Individual or Business
Country or Territory:
Payee Full Name:
Street Address:
Postal Code:
City/Town:
(Tick another Check Box)
Phone:
Email preference: (optional)
How did you find out about Google AdSense:
(Tick the 3 Check Boxes)
STEP 4. Click Submit information button
STEP 5. Your account information will be presented to you. Since we assume that you have already created a GMail account, select the radio button that best describe you. And in using your existing Google account, enter your email and password on the provided window and click continue.
STEP 6. Finish. You will have to wait for email confirmation within 1-2 days review. Congratulations! You now have a Google AdSense account.
For more information about Google AdSense, visit Google AdSense Help. click here