You will need a email account in order to do this tutorial, if you do not have one please make one. (gmail.com, yahoo.com, hotmail.com are all good free services)
First, go to http://www.dyndns.com on your webbrowser and click "Create Account".
Fill out your information, your choice of username/password/email. (Make sure email is real, you will need to confirm a link) After your done, click "Create Account".
Go to your email account that you picked to sign up with. (Example mine was ddosertutorial@gmail.com)
Click on the email in your inbox called "DynDNS.com..." (If its not in the inbox, check junk mail)
Once the email is open, click on the confirmation link.
Once you clicked that link, you should see this "Account Confirmed" page. Now log into your account.
Once logged in, click "Add Host Services".
Now type in your choice of hostname and domain to use (It doesnt matter what it is, your choice completly). Then click the "Use auto detected IP address" link. And last click "Add to Cart".
Now click the "Next >>" button.
Then click the "Activate Services >>" button.
Now you should see a screen like this showing your hosts on your account, you should see the one you just added, if so then congratulations your done, if you dont see it, then go back and look what you did wrong or skipped.
Note: You will need to go back in your account and update the IP details of the host if it changes in order to get into ddoser and have your zombies connect to you. (IPcow.com to check your IP to see when it does)