Joomla 2.5 - Modify registration form and logic

Question

Hello I'm new to Joomla and I want to change the way an account is created (in Joomla 2.5):

1. Change the registation form (remove one or two fields)
2. Change the registration logic: I want to add more stuff in the sent email (and a pdf attachment) and also i want to call some other functions (or make extra requests), analyse the result and then return the response to the client.

What ways are there?

Answer 1

Had an earlier answer for an earlier version that didn't apply, but found this tutorial to get myself up to speed. it lists all the files, etc. that you need to make changes to, but doesn't mention your email requirement. To do that, you'll likely have to look at function register($temp) in components\com_users\models\registration.php