I find it very helpful to preview the ride using ridewithgps, if I the route is available beforehand. Seeing the elevation profile in advance gives me a much better sense of what to expect.

Two of the clubs that post a ride schedule use rating systems: flat, minor hills, moderate hills, steep hills, long climbs or very steep for one, and FF-Fairly Flat, LH=Little Hills, MH=Medium Hills, BH=Big Hills for the other.