new member Registration form - how to add text fields for address, telephone, brief reason for joining.

Hello

The site I am building is a private local community group's membership site. I would like people who sign up to join the site to fill out additional fields including as examples:

* telephone

* address

* text field for a brief reason for joining.

This is to ensure only people local to the community group, geographically speaking, can sign up. 

I would like some or all of the fields to be compulsory. Is there any help on this? or can someone point out where to make these amendments, please?

Regards

Robert