I know that you like A girl, so be her good and
loyal friend first, and observe how she responds to your
friendship. Treat her like you would normally treat your best guy
friend or your best buddy. 
If she responds by giving her friendship to you, you'll got a
chance.
If she don't bother to return her
friendship to you, it means she is not interested in you.
Hmm...being polite and courteous to you doesn't means returning her
friendship to you, people whom you should consider as your friends
are people who are honest about their emotions. They don't bother
to hide their emotions, their personality, their behaviour and
their thoughts from you. People whom you should be wary about are
people who pretends, people who hide their true intentions from
their actions, people who keep you guessing about their friendship
towards you.
Romancing a girl is one way to go after a girl only when the girl
also has a bit of liking for you.
The other way is to be her friend, her good friend...and
she'll realised that you actually get along very well with her
despite your ugly-ness, short-ness and poor-ness. She will be
attracted to you if she's not blind, deaf and stupid by nature.

If she's materialistic or have a bad personality, you should go for
one who doesn't...else you are heading for disaster and I advise
you to go to Indonesia Islands...cos I heard that some Volcanoes
are going to erupt soon. :p
Have faith in yourself and be the cool guy to her. Being cool
doesn't means being quiet and act like a gangster in a corner.
Being cool is about behaving true to
yourself...your own character...the real you. Being cool is
something you do everyday, like...whenever you are with your family
and best friends. 
Be yourself and if she's not attracted to you, I'm sure someone
better will be. 
Good luck. 