DIsney is awesome. Yacht club is really a good hotel your kids and you will love it. Plus it's a 5min walk to Epcot through the back entrance, to the best part of Epcot.
1. Outline your itinerary for the week. Don't wing it. You shouldn't micromanage every moment of the dya of course, but just outline a general schedule of... "Day 1: Magic Kingdom, Day 2: Epcot, etc" I assume you've got park hopper passes? If you don't, get them. Sure, they're pricey, but especially because you're staying at Yacht Club, the flexibility of being able to walk through Epcot every day is worth it... Also Epcot has a Starbucks if you want a coffee fix in the morning. When I went last, I'd walk to the Starbucks at Epcot and get me and my wife coffees each morning, it was great. My wife and I would also go for runs in the morning and so running from where we were (Boardwalk) around Epcot in the morning was great, especially when it was dead.
2. Once your itinerary is figured out, and you should do this soon, SIGN UP FOR YOUR FAST PASSES. This is vital and it helps give you an outline to your day. You get a certain amount of fast passes each time of the day (like 8-11, 11-2, 2-6 or something), and so you schedule those rides you want to go on at those times and it helps map out your day in the park. Maybe when you get to Magic Kingdom, you have a 9am Pirates of the Carribean, so from 8-9ish you do your thing, soak up the entrance, take photos, wander around, etc... then you go do your fast pass ride, then by 9:30 - 11 you start working over to Frontier Land where you go on BIg THudner mountain or something, waiting for your 11:30 Splash mountain fast pass... then get lunch ... then wander over to Fantasy land for your 2:30 pm Mine cart ride, etc. Obviously, set your own schedule with what you like, but this helps provide a good structure to the day... and it means you get to ride what you want without getting exhausted just waiting in line.
3. Plan and reserve your dinner reservations now. It's good to have dinner planned out every day, if you need recommendations happy to provide some. I went with my wife a couple years ago, and we had dinners planned every day, but also scheduled a couple lunches too, and then went light on dinners those nights.
4. Epcot is amazing as an adult, love that place. If you like drinking, even if you're with kids, epcot is a blast to 'drink around the world,' and IIRC, Yacht Club is right off of Epcot in the back entrance, so it'll be perfect for you.
5. You're across from the Boardwalk. It's a good place to go with kids for easy dinners and night time activities, just a pleasant place to be at night. My wife and I stayed there when we went and had a good time.
Don't bother renting a car. Take the shuttles and busses. Yacht club isn't busy and it's a convenient bus ride to most places.
Also, DIsney SPrings is worth going to one night. It gets busy but it's good to get dinner at a "non theme park" and it's nice to wander around the shopping areas. They have good stores there.
Fellow Carousel of Progress fan here. I fucking love how cheesy it is. And yeah, that + people mover... get out of the heat and relax for a half hour. Perfect rides to recharge on.