There are busses going to the parks every 30,min.
Last bus leaves the parks 1 -2 hr(differ) after closing.
In crowded periods there are 1 bus,for 1 park.
At slow times, 1 bus can go to (eks),Magic Kingdom & Studios.
These busses has no official times,but has always leaved the hotel at approx.10,min,past the hr.(8:10-8:40-9:10-9.40) and so on.
The bus stops (at hotels),before they reach the park(s) in the following order.
Hilton Orlando Resort Lake Buena Vista
Royal Plaza Hotel.
Doubletree Guest Suites
This was the LATEST route that was done when i was there in April.
On all my previous visits, one bus,did All the DTD hotels in this route.
Hilton Orlando Resort Lake Buena Vista
Royal Plaza Hotel.
Doubletree Guest Suites
Best Western Lake Buena Vista
Regal Sun Resort-Downtown Disney.(former Grosvnoir)
The Buena Vista Palace Hotel & Spa.
There are also disney water park busses,and buss to DTD at night.
Ride times to the park are about 20-30 min.
Some PS: If You want an midday break,and return to Your hotel At Mid day,it seems to me like the busses are only going back to the hotels hourly.
At MK the bus stops at TTC, so you need to take the monorail or boat after the bus ride.
Have an Magical Time.