Display certain blog categories in a feed on page

I see how a lot of people create a newsfeed from other sites. Is there a way to create a feed of a certain category of my own website’s blog posts on a page.

For example, if I have an Aromatherapy page, I want all the blog posts under the Aromatherapy category displayed in a feed on the left side of the page.

Are there

a. any simple plug ins that do this?

or

b. php coding instructions that a newbie could follow? 🙂

Thanks in advance!