P.S.
Invest in a large monthly desktop calendar. Once you get your syllabus, write down when all your assignements are due. I would use this to add on family events and appointments, as well as meal planning. This will give you a bird's eye view of your life the next few months on what you can commit to and what you can't.
Meal plan for the entire semester. For dinner, I rotate beef, pork, chicken, 2 fish/seafood, 3S (soup,salad,sandwhiches) and junk food night a week. I suggest these type of cookbooks: 6 Ingredients or Less, Betty Crocker Basics, Crockpot Recipes. Write down the book and page number for each recipe you want to use each day. So each day, instead of asking waht's for dinner, you can just look at your calendar, get the correct book, turn to the page and dinner is half done! This will also help with your shopping list.
Go with paper goods. You can recycle them if you are worried about the environment.
I got used to my laundry room turning into my personal wardrobe. While I hate pulling out clothes directly from the dryer for somethign to wear, I did keep stacks of clothes on the work table in there and kept a good supply of hangers on the rod.
Getting up before everyone else can give you an extra hour or 2 of study time. But it sounds like your girls are in school full time so you shouldn't have to worry about lack of study time.
Take breaks, esp if you ahve to write alot of papers. If I stare at a computer screen too long, my eyes start crossing. Either walk around the block or do a minute of jumping jacks or sit ups to get the brain juice flowing again.
As for housework, I limited myself to 30 mins a day. Anything that took longer than that, it had to wait. While this may not seem like alot of time to manage a house, you would be suprised the kind of housework I got done in 30 mins. I invested in alot of Swiffer dusters. I keep a container of wipes and disposable toilet pads in each bathroom for quick cleaning.
gl and congrats on taking a step in a great direction of your life!