Add / relate an image to a page

Hi everyone,

I’m looking for an easy and simple way to attach an image to a page. Right now I’m using Custom Fields where I insert the image path and then I have some PHP code in my page.php where it finds and displays the image but the people I’m creating the site for are having a seemingly hard time figure out how to do it right. So, I was wondering if there were any plugin available where you simply could select a image (possible from the media library) as the default page image and then be able to call something like get_page_image or some like that on the page?

Hope I’ve explained everything alright otherwise, please let me know.

Sincerely
– Mestika