The simplest way is to do it manually, following the old tradition to quote and link interesting content. It is clearly not auttomated, but you can be very creative and take different efforts in every article.
The modern method is to import articles offered by sources via RSS. In AutoTweet and Joocial, you can add any number of feeds, apply filters, choose articles, replace keywords, schedule, modify the article creation with templating and finally share them to your social networks. In this way, you can define your own way to curate and share content with automatted tools and curating content according to your definition.