Mendeley is a free reference manager and academic social network that can help you organize your research, collaborate with others online, and discover the latest research.
ProCon.org is a nonprofit research organization that presents pros and cons of controversial issues in a nonpartisan format. There are currently 42 issues being covered in a comprehensive manner. The site organizes each issue into sections like "Did You Know?", lists of Pros and Cons and then moves on to background information, media references and relevant video clips. There's a lot of information here for students to gain enough perspective to make their own decisions about issues.
Evernote is a great tool for teachers and students to capture notes, save research, collaborate on projects, snap photos of whiteboards, record audio and more. Everything you add to your account is automatically synced and made available on all the computers, phones and tablets you use.
"Research shows that skilled readers use a set of learning strategies that help them make meaning from text. Into the Book provides you with tools to help elementary students learn to use these strategies in reading, the arts, and across the curriculum."