On which page do I apply Uni Email?

I have created a user area where each user completes a registration form, but I want to be able to send an email to the user to say thanks for registering and another to the site owner informing them that they have a new user.

Data assist has created a registration page and a detail page that is displayed once the form is submitted. Now, to save me from destroying any work I have got done so far, can you tell me on which of these two pages I need to apply the universal email?

When I apply it, where should the code be? Eg: before the insert behaviour, or after? I ask this because I have in the past struggled to make this or similar things work. I either get an email with info as entered by the user but no data entered in to my DB, OR, I get data entered in to my DB, but no user info in the email received. It's as though the info from the form has been used once and is no longer available for the next process :(

A thought: Is this where DW's 'sticky text field' comes in to play? Does a 'sticky text field retain info for subsequent processes?

Many thanks.

Mat