Drupal 7.8 customising user.module I am going to build a site using Drupal 7.8. I have some knowledge in PHP, but it is my first time I use Drupal, so I would like to ask your help regarding some basic functional questions I have


I want to have 2 tabbed blocks in my first page. One for "log in" and another for "sign up".
To create this blocks:
For "log in" block it s easy: I will use the out of the box functionality as is (removing create new and request password).
For "sign up" block I would like to remove and add some fields.
Is there any way to find inside user.module the fields used for "username","password","email" etc. and try to use them in my own module?
What are the minimum requirements to use these fields? In other words, if I find the name of these fields, can I use only the names on my module, or I have to override a form/function that maybe contains these fields?
I want to use these fields, but finally for the submission in the database I 'd like to use the default submit functionality. How that could be done?
3.And one last and very newbie question! Forms are implemented using functions or can be stand alone?
So to use an existing form, I have to find in which function it s declared or I have to override only that form?
I know that these are basic questions I should already know but after searching in google, I didn't manage to find a clear solution that works. Could you please help?
You can also use fields to add additional fields to a user or user the profile2 module. There's a good chance, that you don't even have to code a line ;-).

If you need: You can change any form in Drupal with hook_form_alter. This way you can add more functionality to the sign up form.