its up to your body
did you happen to see the cadence's during the paris-roubaix? these guys are like egg beaters over those cobbles. anyway, you should comfortable spinning along at 90-110 rpm, and you shold be able to sprint at north of 120. it takes a computer, and alot of practice to get comfortable spinning high rpm's. bike fit is crucial. working on a trainer is a great place to increase rpm's. your ideal cadence is a function of your physiology. you should be spinning at an rpm that minimizes muscle tension, without stressing your cardio system too much. finding the balance is part of training. as for climbing: there is no rule of thumb. just compare lance in the alps verses almost anyone else. his legs are a blur, while others are standing and pushing a slower rpm. alot depends on your body type