Extending Member Data & WishList Integration

I want to extend the information that I store about members. I am new to both WordPress & Wishlist. It seems from my discussion with WishList support that it does not extend the db however I think I must be able to do this in WordPress…since it’s a database I had assumed that I can somehow define extra fields against the member table? So this post is about both products and I will also post on the WishList forum so, hopefully, I get answers to all aspects. The questions are these:

• Can I extend the data stored against members – and how?
• If I can when Wishlist handles membership registration & Renewal how can i seamlessly request all the manadatory data required of a member? I don’t want to charge soemone before I have all the information that we require?
• When a member maintains his data how would he do this?

Has anyone done something like this and what advice would you give? Or, perhaps there’s some documentation somewhere?

Many thanks……………………. liz