When you arrive in Warner Springs on Route 79 from the south, there will be a "Warner Springs Ranch" sign on your left. The front desk will be on the right just after the main gate and across the street from the gas station/store (look for the parking lot).
There are directions and maps available at:
Maps & Directions
If you want to use Mapquest, Google or Yahoo Maps:
Mapquest
Yahoo Maps
Google Maps -
Google Satellite image
Once at the resort, you won't need a car for seminar activities - the daily training and evening events will take place at the resort. You can certainly have a car if you would like one, but it may be more efficient to organize rental cars or rides with others. For those cabins with more than one car there is also some additional parking across the road at the golf course (on resort property).
Check in for the resort starts at 3 pm, however if you get there earlier, they will let you in to enjoy the facility, you will just have to go back to the main desk to check in after 3 pm.