Update Checklist Thing

Hey all,

Ok, I want to do somthing, but I dont know how (or even if its possible).

I want to create a payment program thing which tells a group of people if they have paid some money for somthing. I want to be able to have a sort of admin section which a user can check off who has paid by their name (with a checkbox) and then click update or somthing and then it updates a list of people with a green tick or somthing by their name.

I would also like to be able to put a password on the admin section bit.

Is this possible? If so, how can I do it (please tell me step by step or give a URL of a tut)