I used to work for a climate change website. I would write their stories by getting interesting news stories from other websites, such as AP and Reuters and just rewrite the news articles so they were the same story just told slightly differently. We did original stories too but the point is if you look at most websites like Yahoo and MSN, their news is just other stories from other sources they feed to their readers. Knowing this should help you find the stories you need for your website.
I think the key is having news stories targeted at your audience that will keep them engaged. Go for quality. If you need any more advice just PM me.