The hotel usually has a fairly large sandwich board sign with upcoming EMHs and at which parks. It's also printed on a sheet they give you in your packet at check in. They seem like they want to make sure their guests know about it, and they always make a point to tell us about it at check in.
Also, beware the monorail!!! We conveniently "forgot" how it worked at DL, after a great trip to WDW staying at the Poly. Some nights, we just rode the monorail around, looking at all the amazing views of the Grand, the Lagoon, MK, the Contemporary and the Mary Blair murals. So, we wanted to do a roundtrip monorail ride at DL, just to kill some time, relax and enjoy the sights. We eased over to the DTD Monorail station from our hotel rooms, kinda still a little groggy from our midday naps, rode the monorail to Tomorrowland and... they kicked us off!! It's only round trip if you start inside DL, not at DTD. We kinda forgot that? But they said we could get off and get back in line to go back to DTD and we get off and I swear the line for the monorail was so long it spilled out past Autopia. It had to be over a 30 minute wait at least. So, we ended up having to walk from Tomorrowland all the way back to DLH!! At least we weren't wearing our PJs!!