When traveling with an infant/toddler, we always found it easier to drive our car to the parks (If driving to Disney World). We didn't have to worry about folding strollers and carrying small children on crowded buses.
Different resorts offer different types of transportation. Before booking, consider which park you might visit most and ask your agent about available transportation to that park. It might be worth it to pay slightly more for your resort and have more transportation options or better bus stop locations.
You cannot get from Disney Springs to a park via bus. You must go to a resort and transfer.
The less stuff you bring on your transportation, the easier time you'll have. Some people don't realize (or forget) that they can pick their merchandise up at their resort hotel, instead of carrying it back with them. Such a helpful feature for guests!
Use all forms of transportation while on your trip. Bus, water taxi, monorail, and the ferry to give your kids different experiences they might not get otherwise. Plus they may make for a fun family evening ride after you leave the parks
For families with small children, choice of stroller is a big deal. We love our baby jogger double stroller. Literally folds up in 3 seconds. We've seen so many families struggle to get on and off of buses/boats so many times.
You can ride the monorail, boats, buses and water taxis for free!