I'm not a lawyer but I am a journalist. There's no cut-and-dried definition of "fair use" (though there have certainly been some rulings about it) so you kind of have to use your judgment as to what is "fair," just like the many blogs (and full-fledged media outlets) who do a lot of quoting and cut-and-pasting. And really, at the end of the day, as long as you aren't reproducing wholesale and are linking and crediting properly, it is unlikely a site of this size will be in any trouble, and if it did, the trouble would begin and end with a polite request to stop doing it.
But I would say if you aren't repurposing the information or using it in a way that illuminates your own opinion/information in a unique way, be conservative. I sometimes to share philly.com stories and will usually only include one quote, or I will omit a lot with ellipses if there are two things I want to highlight. Don't do it as much on the new site since shared links render with more info now.