Internal buses start around 7am(might be as early as 6:30 though) and run until 2am. The Mk boat starts about 1/2 hour prior to park opening and runs until 1 hour after closing. The WL/CR/FW boat starts at 6:45am, not sure what time it stops but I think it is arounf 10:30/11:00pm.
As with any Disney Transportation times are subject to change and when in doubt check with an operator of that type of transportation. Desk clerks will answer as best they can but are not always accurate, if you want to know about bus routes ask a bus driver, if you need info on the boats on Bay Lake, ask a Bay Lake boat CM.