Symbaloo allows you to bookmark your favorite websites and arrange them into tile boards that you can share or keep private. Symbaloo calls the tile boards webmixes. You can create multiple webmixes arranged according to topics of your choosing. You could create webmixes about topics to share with your students. Or you could have students create their own webmixes and share them with the class to help everyone learn from each other’s research.
Symbaloo does offer an education version, but the education version is not free except for individual use which doesn’t make it different than signing up for a regular Symbaloo account.