Traveling between resorts will require either personal transportation or use WDW transportation.
If you are in a park, you can easily just take the bus from that park to any resort. If you are at SSR, you can bus (or walk) to DD and get the bus to VWL there. If you are at VWL, you can take a boat to MK and then a bus to SSR ... or ... take a bus to DD and walk (or bus) to SSR.
I'd allow an hour travel time is you'll need multiple bus rides.