I am not sure what you have tried so far, however the correct way to setup an account is to follow this link to download and then install iTunes to your computer http://www.apple.com/itunes/download/
Once you ahve the iTunes software downloaded then installed all you need to do is open iTunes then click Store and click Create Account.
Next just read through the Terms & Conditions and check the box if you agree to the terms then click Continue and fill in the form to create your free Apple ID, then you will need to enter your payment details so you can buy apps, songs etc and that is it.
Once that is done you can then start shopping from the iTunes Store.
If that is what you have done then you have setup the account correctly and are all set, If however you got any errors or had any issues let us know