You can take a look at one way that I’ve included lists of articles within a category my site and click the categories you see listed in the box at the upper right corner to see how those categories information is also displayed. Is this what you are talking about?
Or do you want a list of posts within that category to be displayed WITHIN your post?
I’ve been trying to do that for ages and have not had luck. I can get some things in the sidebar, and I can get related posts in the sidebar through the use of Customizable Post Listings Plugin, but these are on the templates and not within the post itself.
There is a new plugin called In-series that kinda does what I want it to do, which is connect a series of articles together, which could be used to display a category of articles, though it might be cumbersome to use that way. But it works. You can see an example of the usage on the bottom (above comments) on this page on my site.
If these are close to what you want, then I can explain further how to use them, or someone else can.
