I grew up training without a computer. My coach was big on high cadence, low gears and smooth pedaling action. Today I'm 55 and have good knees, pedal very smoothly and use a cadence computer. I pay more attention to cadence than speed. For the new rider a cadence capable computer will help you train correctly as will a heart monitor. One of the attributes that makes Lance such a standout is his ability to maintain cadences are 10/15 RPM higher than his competition. Also it pays to have lungs the size of garbage cans. Higher cadences can be quite lung busting.

A good book to get is The Lance Armstrong Performance Program by Lance and Chris Carmichael