Different registration forms for different types of users

This is my first time building a site with Drupal (7). I have plenty experience with LAMP, HTML/CSS and javascript, but I want to make sure I am doing things the 'Drupal way' before I start hacking together a custom开发者_JAVA技巧 solution unnecessarily. I've searched forums and modules, but have come up empty.

The site I am building will have different tiers of users: students, teachers, and parents. The difference between these users is:

1. The information collected during registration, and
2. The pages the user's have access to.

I think at least part of the solution lies with creating roles for each type of user, but it seems Drupal only has one registration page for all users. How would I create a different registration form for each type of user? What is the 'usual' way of assigning roles to users automatically?

I know this is late the game here but I thought I might refer people to the "Rules" module... Instead of thinking about this from the "user-specific" registration form perspective, think of it instead from the perspective that you still have only 1 form but with additional / optional inputs, whereby subsequent actions (rules) are then enacted upon depending on the values of said additional / optional fields.

You might also check this out, too: how do i make diffrent registration form in drupal?

I'm just updating my answer as I see it didn't apply for D7.

I've just begun developing a D7 site with a similar request.
There seems to be a module which should fit perfectly, although I still have to try it:
http://drupal.org/project/profile2

Good luck with it.