Don’t forget the power of positive reinforcement. For the things that seem small – acknowledgement, at least and rewards. He may be feeling overwhelmed already.
To help remember to hand in assignments, around fourth grade we started with color-coordinated folders and notebooks (Staples has different colored composition books or he/you color in the white part). WE’d coordinate the color on his class schedule: foreign language was orange; math, blue; etc. (Have him chose colors – there will be a trigger). If there was homework in the folder due the next day, we’d put some kind of note on it (like an “H” that would then get crossed out) or just a post it so he’d learn to take out the folder at the beginning of class, he didn’t have to remember if there was homework in it. The note was already there from the night before. It actually helped, became habit and our son still uses color-coordinated folders (he’s in college now).