Symbaloo is an excellent service on which you can visually organize your favorite and most frequently used websites. 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. Symbaloo offers a free iPhone app, a free Android app, and free Windows mobile app that you can use to add to and access your webmixes anywhere.
Symbaloo offers more than thirty tutorial videos to help users get started and understand all of the features of the service. That playlist is embedded below. I also recommend reading Travis Towne's 11 Helpful Hints for Combining Google Drive With Symbaloo.