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Basically, when you get the password and userid out of the DB, you grab the other stuff too and use that to put content on the welcome/post-login page.
Sorry to be so vague, but I don't know at all what you're trying to do, with what software or anything.
One very common toolkit for this is PHP and MySQL. You might start by browsing the PHP forum library [webmasterworld.com]. It might just confuse you, but hopefully it will get you headed in the right direction.