Here is one of my favorite website for science articles.
Science Daily is a great website for keeping up on the latest science and finding science related articles. As you have probably experienced, students are not always very experience in evaluating the credibility of internet sources. Some nice features are:
1) All articles are second-source reports published only in reputable, peer-reviewed science journals.
2) The articles are categorized and sub-categorized to easily find topics of interest.
3) At the end of each article is a citation that can be automatically formatted in APA or MLA style.
4) There are a variety of RSS feeds to choose from, such as health, technology, environment, etc…