I don't know if you're having similar troubles in being organized that he's having but maybe you can get "twin" calendars or organization systems and work on keeping track of what assignments one has and when they're due and work together to learn how to study effectively?

Maybe make study dates (with lovely food :-) that are fun or invite other school friends/couples to get together and everyone kind of study together as if one were in the library? You could have various snacks and maybe a couple sets of headphones for those who study better with music and "stations" where individuals or couples could work.

Being encouraging and sharing your own work (my husband and I read a book aloud and discuss it when we're on long road trips or when he needs me to massage his damaged, painful foot) can be lots of fun and helpful as it gets another person's ideas and perception. I can't tell you the number of times my husband's thoughts helped me write my papers; we'd talk about them and I'd try to explain to him the information (history or English) while he'd try to understand (he's an engineer/scientist) and I often got a unique point of view to work from (Newton's Third Law to explain the Fall of the Ottoman Empire) and it was VERY comforting to be able to continue to discuss what I was working on and to see the progress I was making writing it, etc.