Newbie cadence question

You will be a more efficient rider if you are spinning around 90-95rpm's.  Which means you will be able to sustain an effort longer and have more left for the run with the higher rpm's.

Dave 

Besides cadence you also need to factor in your HR or perceived exertion level.  Doesn't do much good to spin away in first gear and not go anywhere, or on the other extreme, max out your HR in too high of a gear. 

As your cardiovascular conditioning/strength/pedaling technique improve you'll find you can ride at the same cadence & exertion level in higher gears (= go faster).

Mark

No one rule applies to everyone, but many cyclists benefit from a higher cadence. It's worth giving a try, easiest way is to get a cycling computer with a cadence readout, like the Cateye Astrale 8.