Disney Transport is a remarkably easy system to understand. You'll have NO TROUBLE. There's no confusing stuff to worry about, for your average transportation needs.
At your resort, get on the bus labeled for the destination you want. It's really that simple. If you see a bus that says "Magic Kingdom" on it and you want to go to Epcot, don't get on that bus. But if you want to go to Epcot, ALL ABOARD!.
There are no "routes." The MK bus goes only to MK, and so on. There are also no schedules or time tables. Buses to/from each destination run about every 15-20 minutes. So in other words, you'll never say to the kids, "Hurry up, we have to catch the 9:30 a.m. Disney-MGM Studios bus," because there's no such thing. You simply wait for the bus you want, confident in the knowledge that one will be there soon.
When you exit each theme park, there will be a large area set aside just for buses going back to the resorts. Each resort will have its own area, and each will be well-signed. You just get on the bus going back to your resort, and that's it.
The only way it can possibly get confusing is if you want to go from resort to resort ("resort" is Disney-speak for "hotel"). There are no buses that go from resort to resort (except of course for resorts that already share buses with each other, such as the All Stars sharing with each other). Since there are no buses from resort to resort, if you need to get to another resort you have to take a bus to a theme park, and then from there take a bus to that target resort. In other words, let's say you have dinner reservations at a restaurant in Animal Kingdom Lodge (AKL). You could get on an AK bus at All Stars, ride to AK, and once at AK go the area for departing buses and then go to the stop with the sign that says AKL, and get on that bus. You'd have to do the same for the way home. From AKL, you could take a bus to any park you want (as long as it's still open), and then from that park catch a bus back to your resort.