Modifying registration, profile pages

I would like to modify the registration page and the corresponding profile page for those who sign up (register) for my blogsite so that they require additional information (site “theme” related to sailing)

I want to be sure that I understand what is required… I’ve done server side programming some but I am no php developer. I’ve had some success so far with modifying the admin pages but those changes have been minimal and this will involve storing the data provided to the new fields. As well, I’d like that data to be modifiable via the profile page.

Here’s my approach… could someone with the chops advise if this looks right?

1) Add new fields to the wp_usermeta table first
2) Add fields to registration form in wp_register.php file
3) modify the registration-functions.php file (in wp-includes)
4) Add fields to profile.php (in wp-admin folder) so that user can update them.

Anyone out there interested in working with me on this for pay? It’s really more than I am comfortable with – I feel like I can see what needs to be done, but am not totally comfortable with doing it. I’m primarily the designer/developer for the front end, but I’ve managed to get most of the site working as required (really my first time using WordPress)

You can contact me at webmasterATschoonermaggiebDOTnet

doing the obvious, of course…