Mechanics of Broom Flight

[squeakinby]

No: HPFGUIDX 101324

How does one operate a broom?

I imagine that they are steered much in the same way you steer a 
motorcycle--by leaning.  In the movies (sorry) Harry is seen to pull up 
on the stick to slow down, much as you would a horse but why doesn't the 
broom go ballistic like a jet?  How does it know you want to slow down 
instead of changing altitude/attitude?

How would you increase your broom speed?

Jem