Google News Sitemap Feed With Multisite Support

Sitemap: http://example.com/sitemap-news.xml

The best option is to submit the sitemap via Google Webmaster Tools. Please read News Sitemaps: Submitting a News Sitemap.
Do I have to use it in order to be included to Google News?
It is not the requirement but highly recommended by Google. Please read News Sitemaps.
Where can I find more information on Google News?
Technical Requirements /
Submitting Your Content /
Additional Tips /
Troubleshooting /
Search Google News Help articles
How do I get my latest articles listed on Google News?
Go to Suggest News Content for Google News and submit your website.

Open news.google.com
Then type site:example.com and click ?Search News? button. (Replace example.com will your blog or website URL)
If results are displayed, implies blog is included in Google News index otherwise you can apply for inclusion.

My WordPress powered blog is installed in a subdirectory. Does that change anything?
That depends on where the index.php and .htaccess of your installation reside:

If they are in the root while the rest of the WP files are installed in a subdir, so the site is accessible from your domain root, you do not have to do anything.
If the index.php is together with your wp-config.php and all other WP files in a subdir, meaning your blog is only accessible via that subdir, you need to manage your own robots.txt file in your domain root. It has to be in the root (!) and needs a line starting with Sitemap: followed by the full URL to the sitemap feed provided by XML Sitemap Feed plugin. Like:

Sitemap: http://example.com/subdir/sitemap-news.xml

If you already have a robots.txt file with another Sitemap reference like it, just add the full line below or above it.
I see no sitemap-news.xml file in my site root!
The sitemap is dynamically generated just like a feed. There is no actual file created.
I see a sitemap-news.xml file in site root but it does not seem to get updated!
You are most likely looking at a sitemap-news.xml file that has been created by another XML Sitemap plugin before you started using this plugin. Just remove it and let the plugin dynamically generate it just like a feed. There is no actual file created.

If that's not the case, you are probably using a caching plugin or your browser does not update to the latest feed output. Please verify.
I use a caching plugin but the sitemap is not cached
Some caching plugins have the option to switch on/off caching of feeds. Make sure it is turned on.

Frederick Townes, developer of W3 Total Cache, says: "There's a checkbox option on the page cache settings tab to cache feeds. They will expire according to the expires field value on the browser cache setting for HTML."
I get an ERROR when opening the sitemap!
The following errors might be encountered:

404 page instead of my sitemap-news.xml

Try to refresh the Permalink structure in WordPress. Go to Settings > Permalinks and re-save them. Then reload the XML Sitemap in your browser with a clean browser cache. ( Try Ctrl+R to bypass the browser cache -- this works on most but not all browsers. )
I like the plugin! It brought me tons of traffic from Google News!
Donate via PayPal. Any amount will help to keep the code updated. Thank you!