Registration blanket, database, info, wordpress, mySQL, e-mail

I'm making websites for a company where users have to "register" with names and a lot of different information to attend the event. (It's a video-event - info would be name, e-mail etc.)

I now got a Wordpress webpage, at the blanket doesn't necessary need to be on the site, but can open in a separate window.

I need to, somehow make it easy for admin to look at the users who registered, send them e-mails etc. Make a list of everyone who register, for the admin to see.

How would be the easiest way to do this? I know how to make a form, and pull the information into the database..

Any good ideas, plugins or examples??

Thanks