I looked around and most of the tutorials I found are for blogging with Ditto.
It’s pretty simple, though.
You just create a container document in the MODx Manager (just a document with the "container" checkbox marked). Then, under that document, you create one new document for each news story (later you can add doing it with NewsPublisher).
Then, on the page where you want the news stories to appear, you put the Ditto call.
Start with:
[!Ditto?startID=`8` &display=`3` !]
Instead of 8, use the document ID of your news container document.
This may help:
http://wiki.modxcms.com/index.php/Snippet_call_anatomy
Also, take a look at the site in my sig.