there are several way to reach new norcia with main access great northern highway.
1 rent a car or drive your own car companied by road map. you can stop in several places nearby. like bassendean or bindoon or cervantes [on the way to the pinnacles at nambung national park]
2 join day tour which provided by several tour agents in perth, one of them is located at the corner of hay street and pier street, not so far from st george's terrace
3 take transwa bus which has service from and to perth regularly about 2 times per day. here i attached the buses schedule.
New Norcia lies 132km north of Perth. If traveling by car, take the Great Northern Highway through the Chittering Valley and Upper Swan Valley right into New Norcia. (approximately 1 ½ - 2 hrs), or you can take the route via the Pinnacles or the Avon Valley
Transwa bus service runs to and from New Norcia although not necessarily on a daily basis.