using templates for specific pages

Im about to embark on a biggish project and need to be able to use different templates for certain pages. So that way I can use different loop queries on different pages.

Is there a way so I can assign a certain template to each page? Or are all of my pages going to HAVE to use page.php?

Im using 2.9.2 btw, there was only an option for 2.9.1

also – when I click on a post, and it brings up that post, does WP automatically use the single.php template if it exists?