Our shop just got these maps in which I'm extatic about. It shows primary, secondary and trail routes. The primary and secondary are recommended roads to ride on. Its looks better than it is though... the roads don't give you very good coverage of the city, and many are in very bad condition, but its a start at least. They just need to work on connecting the bike paths now.
They are quite complicated sometimes: principal shared paths, perth bicycle network, regional recreational paths.... I would rather they were classified by path type such as: sealed shoulder on road, separate cycle path, converted footpath, bycycle friendly street (actually that last is indeed a classification).
What are people's favourite type of path? Mine is the sealed shoulder - part of the road system itself, so no messing about when crossing roads because you're already on them.
The worst would have to be conwerted footpaths - in fact these shouldn't really be listed as cycle paths IMO - they are too bumpy and I ride in constant terror of a car pulling out from a driveway without looking - I take the road instead.
What I like is the bike paths in the city... the way they are set up here is in the congested areas theres a few short, 2.5-5mi paths you can hop on to get out to the rolling farmlands without having to take any major roads. Most roads here do not have shoulders unfortunately.