Add form / application for new Signups

[qubed]

Is there a way to add a page to the sign up process that is essentially like an application for new users? I would like to have a form that allows a user to say how they discovered the forum.

I would also like the form to include their occupation and website in addition to their twitter account if they have one before joining. Basically a form that allows me to gather more information about the user as my site is invitation only.

Is there a way to do this? If so, how can I go about getting this setup. My php knowledge is minimal, so I would need step by step instructions if so. Dont worry, I am a quick learner. Thanks!