In the past the CM's had only very general info regarding the race & course. Your best bet is to talk to guests who have experience with previous race weekends.
Regarding the race course during regular park hours, runners will enter AK near Conservation Station and run through Asia, past Everest and through Dinoland & exit to a backstage area. At HS, runners from the backlot area through the main entrance to Lights Motor, Action stunt show, down NY Street, past the commisary, and towards the main entrance. Runners will then run through Yacht & Bach Club & enter Epcot through the back gate of World Showcase (behind England). There will be yellow cones along World Showcase and through Future World. There will also be cast members tending to roped off areas designated for crossing the course. They will allow as many people to cross as frequently as possible at gaps between runners.
In general, give yourself extra time for the first few hours on Sunday. Race busses are operated by Mears and are separate from the normal park transportation. AK will generally be the most difficult park to get to, based on the resort you're staying at.