Riding a bike with minimal skills is extremely dangerous.  I've seen riders out there who have no clue how to countersteer.  Crazy.  A good place to start riding bikes is on the dirt.  Read or take courses on how to ride MX, and when you go to the street, you'll transfer amazing skills to the street bike.  Schools from guys like Gary Bailey or Semics are really good resources.  Even the old farts who never rode dirt would benefit from this.  And, it's fantastic exercise.