You've already received some good advice. Here's my two cents after having 3 c-sections. You should be OK taking care of the kids, as long as you don't try to overdo it. I definitely agree with setting up a station downstairs for naps and diaper/clothes changes. I tried to limit my trips up and down stairs to once or maybe twice a day for the first week.
Also, if your toddler tends to like being carried/held a lot, I'd try to break the habit a little before the new baby comes since you really shouldn't lift anything heavier than your newborn for a while (not that I never did it, but tried not to). Also get him used to getting up into the carseat, chair at the table, etc. by himself if he doesn't already - emphasize he's a big boy (not that you can't do it because of the baby).
I was able to do the basic household tasks, including dishes and laundry, but I made DH carry the laundry baskets up and down the stairs. I also didn't try to tackle grocery shopping for a couple weeks at least (too much lifting, etc., especially with 2 kids with you).
Taking care of the kids will ensure you're staying active enough, but just be sure you rest enough too. Your body will still be healing.
While I do think you can manage on your own, I strongly advise that you have someone "on call" just in case you have complications and need more help. I had planned on doing it myself after my third c-section, but I had complications and did end up needing someone to help out. Even with that, I did do most of it myself, but it was nice being able to have someone help out with the older ones especially. You may even just want to plan on having your mom come for a half day a couple times the first week home even if everything goes smoothly.
Best of luck!