like you, i am having my third with older ones at similar ages! good for you for thinking about this. i am super protective of my post partum time having worried about PPD from the beginning and thus seen it wreck up people's times. not that it can be prevented by having meals in place but for me, every little bit that makes life easier that first month is what i focus on and go for!
you can use mealbaby.com or just send out a spreadsheet for people to sign up for meals. i like for there to be a sign up sheet with specific foods and take out places requested for 30 days. it can start the day, week or whenever after the baby is born. like, if you have family or a post-partum doula helping the first week, get the food started the week. I agree with having your freezer stocked and directions on cook times either written on the package in the freezer or a list with directions hung on the freezer. so much easier for a helper to figure out.
if a good friend is dropping off food one day, i have thought about asking her for a little one hour of playtime with my kids- outside or in their playroom, wherever. she doesn't have to take them anywhere, just some attention and time with her and her kids, perhaps. my girls could burn their energy this way and i could have a shower/rest or focus on the babe, etc. i have even considered a sign up sheet for this like the meal thing.
i print directions to using my washing machine for my MIL and my mom so it's easier for them to do my laundry. i have heard some people keep a list of daily items (run the vacuum, sweep the kitchen, unload the dishwasher, wipe down the bathroom sink, fill kid's water bottles, set out food to defrost) on the fridge so a neighbor or friend who stops by can do a quick helpful job.
you could get a post partum massage set up. they can come to your house to do it on day 3 if you have space for their massage table.
have the phone number of a lactation consultant handy or la leche league so you don't have to search for this if you need their support. comfy nursing tank tops and breast pads are great to have.
for ease, i set up a basket of snacks in my bedroom for my older kids (and me) to have access to when we won't make it downstairs to the kitchen or to prepare a full meal right on the usual mealtime. all healthy stuff like larabars, nuts, etc. we don't usually have disposable boxes of food items but i break that rule real quick for post partum sanity and more post partum snuggle time. another basket of new coloring books or neat small toys that they can play with in your room may be helpful, too. we plan to do this and i have already stocked up! i rest for 3 full days in my room though; i do not mess with that bonding and recovery time at all. i totally chill. so, for my girls to remain content, i hope to have things set up easy for them. i know i will want them near by but calm and content. also, i had a stack of books to read to my oldest when her lil sis was a newborn. i could snuggle them both, nurse the babe and read to the older one. it served everyone's needs easily and kept us all connected.
have comfy transition clothes that are really easy to breastfeed in- button down shirts work great. stay in your robe or pajamas when people come to the door to bring you meals so it's clear you are not there to entertain them.
i try to get in the bed by 7pm so I can at least rest and attempt to patch together some sleep over the next 12 hours. can you tell i create a cocoon around my bed and rest time? for the first few days or so, i keep a notepad by the bed to record how long the babe nursed and on what side plus when i slept and for how long. this may sound extreme but i like to have a record and not have to worry or try to remember such details.