How to Add Confirmation email field in magento registration form using class validate-cemail?

The following method allows you to add confirmation email address field in your customer registration or newsletter page.
Create a javascript file called validation.js under "js/email/validation.js"

Validation.addAllThese([

    ['validate-cemail', 'Please make sure your emails match.', function(v) {
                var conf = $('confirmation') ? $('confirmation') : $$('.validate-cemail')[0];
                var pass = false;
  var confirm;
                if ($('email')) {
                    pass = $('email');
                }
  confirm =conf.value;
  if(!confirm && $('email2'))
  {
  confirm = $('email2').value;
  }
                return (pass.value == confirm);
            }],
]); 

Add the new js file into your customer.xml file

On the register form add a new field to contain the email confirmation field "template/customer/form/register.phtml".

*CONFIRM EMAIL
 

Thats all. You are done.

How to add Terms and Conditions in magento customer registration form?

While customer registration sometimes we need to add Terms & Conditon page with checkbox. Here is the code to add terms & condition field to your registration form.

<?php echo $this->__('I have read and agreed to the ') ?><a href="#">Terms and Conditions</a>
<input type="checkbox" name="terms" title="<?php echo $this->__('Terms and Conditions') ?>" value="1" id="terms" class="checkbox required-entry" />

How to add address field in magento customer registration form?

If you want to add address details in your form you are in luck. Those fields are already setup in the "template/customer/form/register.phtml" file, but they are disabled by an inactive if statement that so far has not actually been linked to anything else in Magento. Therefore to enable the address related fields you simply need to comment out or delete the following statements:

<?php if($this->getShowAddressFields()): ?>

and

<?php endif; ?>

Note that there are two occurrences of this if statement. One is around the area where the customer actually inputs their data  and the second statement is bottom of the file around some JavaScript code that sets up the State/Province select.