Some questions – troubleshooting in wp 3

Hi to everyone . I’m new with wordpress 3 and I have some questions.

First I want to say I have installed multiple post type and I like this option from this version very much, but I have a question . How can I add category for new post types . For example if I create “Movies” post type I can’t be able to add categories to this new post. I’ve tried something with register post plugin, with register_taxonomy but it seems to be register a tag system not a category system to the new post type . Can you help me ?

Second question is, how can I configure something like :
When I have access new post type (movies for example) to load these pages instead of by default:

archive-movies.php
single-movies.php

Thanks you, wordpress is the best !