I am having an online News articles site (opinionstudio.net) which I want to be included in Google News. Any SEO service can help n this regard. Moreover can anybody suggest me a list of similar sites (Like Google News) with a high probability to include my site.
You should need to apply your for Google news from google only. Before applying you need to configure every athour page and author list page in your site. If your website is on wordpress then there is plugin available to make special sitemap to submit Google news. Google news doesn't accept default sitemap.
Agree. Before submitting to Google, be sure regarding content. With weak content and with those not updated regularly will lose the possibility of acceptance.
Before submitting your site in Google.News try to make all Google recommendations. Also if your resource is new - is it very difficult to be in Google.News You can read all their recommendations on official site