getting info from checkout page

Hello,

I need to extract some data from the checkout page while a customer is placing an order. What I need creating a CSV file containnig:

customer-id, email address, sku, order, description, unit cost, qty  and few more items.

Which module can help me to get these information? or do I need to extract these information from different modules?



Thanks.

Can an expert give me some comments on this due to having a deadline ?

Thanks.

OK. all I need to know is which module/class handles CSV exporting. I have seen this feature in Admin. Can somebody guide me on this?

Thanks.

Has anybody worked or knows in which module I can access to session information?

what is important to me the session values right before customer clicks on confirm button on check out page.