I personally am not good with using planners, and instead have a big huge calendar on my desk that I write in the due dates of my assignments on. That way it is there in my face and very clear, and I have a much better visual sense of the spacing and pacing of my assignments.
I also use to-do lists, but often those can be overwhelming, so I have a little whiteboard for broken-down to-do lists -- a "to do today" and "to do tomorrow" list that's a little snapshot of the bigger picture. That way it feels more manageable.
In terms of organizing material from the courses/subjects -- I make sure to have a separate notebook for each subject, with my notes clearly marked with the date, ordered chronologically. I'm a very visual person, so at the end of term I will then make a chart or other visual representation of the key points that I need to study, compiled from going through my notes from the course.
All of those above examples are ones that work for a visual learner, and me personally -- so they may or may not work for you! I think the most beneficial thing you can do is to figure out what kind of learner/organizer you are -- how you best retain information -- and find some techniques that work with that strength. You may also find that when you combine TWO learning/organizing styles together, it makes them even more effective -- for example, I find that simply reading something is okay, but having it read aloud (like with software on a computer) while I read along helps me retain it better. Or, when I just listen to someone talking, I get very lost, but as soon as I pair it with note-taking, I retain a lot more information than I would with either technique by itself.