I have no experience with twins but wanted to make a few suggestions that help me get my three out the door on time and point you in the direction of this FAQ
On having TwinfantsFirstly, get your DH involved! We have managed to work it so that my DH goes in to work a bit later (9.15am start) so that he can be with me and the kids until 8.30. He gets up at 6.45 to shower and get himself ready then the boys get up at 7.10 (sometimes they wake earlier) and i take them down to start breakfast. Sometimes the baby is up but sometimes she has gone back to sleep after a 5-6am feed. When my DH comes down about 7.30 he takes over getting the boys washed and dressed while i shower and get myself ready. Then i just have to get DD fed and changed before DH leaves and all that is left to do is get shoes, coats and bags on to be out the door for 8.35am. DH also often has time to check over homework or reading with DS1.
Even if your DH can't be around so much i would look at what he can do and make sure he isn't just getting up in time to get himself ready and leaving all the rest to you. This does mean my DH doesn't get home until 7pm (BT) most nights but i find BT easier than mornings to do alone and sometimes my mum helps me then if she is free.
I also find getting the boys to do as much as possible like getting themselves dressed (while dh oversees and eats breakfast), brushing their teeth and putting on shoes and coats so we dont have to physically do it helps. Your boys may even be able to make their own breakfast for example. I also sort out all clothes and bags the night before.
I always plan my DD's routine around the school runs even if it means waking her early. That way I don't end up with her waking just as we are walking out the house when I won't be able to feed her for 45 mins or she ends up crying the entire way.
IME it is no good relying on a timed schedule that you try to make the same every day as babies rarely oblige with the same length naps or feeds and things change so quickly at this age that as soon as i think we've settled into a predictable routine she changes everything up. Sometimes she sleeps on the school run, sometimes not so i have to be flexible.
Accept as much help as you can. Don't be polite and lose out. You snooze, you lose as my DS2 says. If you can get DH or your mum to have time off to help you after the birth. If mums at your boys' school offer to do pick up or drop off for you or say they will have your boys over for tea, let them. I have had mums say to me if i dont want to disturb my LO from a sleep at pick up time i should text them and they will take my DS home to their place so i can pick him up later and such. People really are happy to help.
If friends and neighbours ask what they can do to help don't be afraid to ask them to make you a meal or pick you up some groceries or whatever. I also find it invaluable when people offer to have my youngest so my DD can get a nap in quiet and I can rest or get stuff done while DS1 is at school.
So excited for you but I'm sure they will keep you on your toes. Don't forget to enjoy it though!