Think of it this way, so you don't get overwhelmed: ANYTHING is better than eating fast food all the time.
What I usually do is meal plan dinners, but plan to make more than we need. Lunch the next day is simply leftovers, plus a salad. Then I make sure we have adequate snack stuff and breakfast stuff (tons of bananas, oatmeal, some ham, some english muffins, etc...) and we're basically covered. This assumes I keep the pantry stocked with basic staples, like flour, vinegars, oils, etc...
Do you get a CSA or hit the farmers' market? If so, try the free meal planner at EatRealGood.com
. If not, you can just pull from some of the recipes there.
There is also a service (paid) called Menu Mailer that literally emails you a meal plan each week, but I didn't love the food. I LOVE the set up and basic idea, but the food itself wasn't yummy to me, which kinda defeats the whole purpose.
If you even start with cooking 2-3 meals each week (just making LARGE batches), then you can eat out of the fridge and get through with your busy schedules.
Good luck with the transition! Just try to stay organized.