I very much like Vork's ideas, I wish I could have read them a a few years ago, as they would've saved me from much time, frustration, and useless self-loathing.

I believe I have one tip of my to add to the collection which is vital and ties in nicely with his advice:

If you like a girl, talk to her about her life and the things that interest her first, not you.

It's likely that your potential girlfriend is interested in you and the things you do too, but talking excessively about what you do and the things you like isn't going to do you much good! Many guys like to think of the dating process as some kind of sales pitch in which you have to market yourself and impress your victim with your talents, intelligence, wit and good humour (and if you're a real bastard, money.) I bet you most of the time girls are happy simply to talk to someone who is willing to listen and care about their lives. If you act as though you are the centre of the universe they will feel turned off or intimidated. That is clearly the wrong approach.

This doesn't MEAN you shouldn't talk about yourself at all!

But what better way to show a girl you really like her than to put her life/interestests/problems in front of your own. Developing an interest in the other person will not only make her like you, but it will also potentially sow the seeds of a great relationship and friendship. You don't have to convert to her ways, simply respect them and accept them.