There are no resort-to-resort buses. So, you'll need to transfer at either a theme park or Downtown Disney.
If the theme park that is closest to the resort you're trying to reach is open, this is usually the quickest way to get there. (The exception is near the park's closing time, when the buses at that park will be mobbed.)
If you're trying to get somewhere after the parks have closed, you can transfer via Downtown Disney. The Downtown Disney buses continue to run until very late, because Pleasure Island and the West End stay open until 2am.
All of the bus areas will have a sign at the front telling you which stop number for which resort. The stops themselves also usually list the resorts that are served by that stop. The buses themselves will also say the resort name on the front and side. (Always read the sign on the bus. Sometimes a bus stop accomodates more than one resort, and you don't want to get on the wrong bus.)
If in doubt, ask any bus driver. They'll go out of their way to make sure you understand how to get where you're going.
For Wilderness Lodge, you can take the bus from ASMo to the Magic Kingdom. From there, you can take either a bus or a boat to Wilderness Lodge. For a bus, ask your bus driver which stop number serves Wilderness Lodge. (This will save you from walking all the way to the front to find the sign that lists the resorts.)
If you want to take the boat (you do, it's a lovely way to get to WL), the boat dock for Wilderness Lodge is between the ferry landing and the monorail entrance.