It's about a 10 minute walk from the Congress Park area. If you are in a different area, you can either take a bus directly to DTD, or take the bus to Congress Park and then walk.
It really depends where your room is. We were staying close to the main lobby last year and got very lost trying to get to DTD. CMs directed us and it took about 30 minutes before we arrived. Never found the correct path, perhaps that would be easier.
if you're on the end by DtD, you can walk to McDonald's and back with breakfast for the lazy bums in your family in about 30 minutes. not that I'd have any experience with that or anything...
There is also a walkway to the Westside at DTD from behind the Turf CLub restaurant. When facing the boat launch the walk-way is to the right. You will take a bridge over the river and stay to your left (golf course on right). It's about a 10 minute walk to Westside from the boat launch area.