How do I get the last post’s permalink from a certain category?

I want to have “top stories” from a couple of categories I have. So I’m trying to get the permalinks from the last story in a category or two. I tried using query_post and then get_permalink but it seems to mess up my main feed.

Little extra, is there a plugin that links a image with a post? I completed a method where I retrieve the last image uploaded to a certain directory at the moment. It would be nice to have a plugin that does this better though. So, if anyone knows of a plugin that links an image with a post without placing said imagine in the post that would be awesome! Thanks!