There is no one way to start...the simple answer is to start. For immediate pay I would suggest applying at Demand Media Studios, WiseGEEK and Bright Hub. The revenue share sites take time to build up revenue but the best ones are Hub Pages, Associated Content and Suite101.
The next "quickest way to earn money" is to look into Internet marketing. There is no overnight riches. It takes time. I would first seek out the up-front pay sites, then rev share and then Internet marketing.