How to get a girlfriend if you're a hopeless nerd

Whatever. Getting women is not a mystery.

Think about the kinds of girls you know. Some of them instantly make you go "bleugh" and some make you go "mmm!" You just have to change yourself from a bleugh to an mmm kind of man. Improve your outward appearance: stand up straight and walk with confidence, exercise to stay in shape, put some effort into grooming yourself and wear interesting clothes and accessories. Physical attraction is just the initial connection. Any girl worth dating long term is going to need an intellectual connection with you. So be aware of weird eccentricities you may have and don't let them out on the first meeting. Of course you have to "be yourself," just be a little more suave the first time. It helps to have interesting things to talk about to keep her interested. Sports, projects you have done, hiking... things that say "I am active and fun" usually work best. Something like rock climbing makes for a good first date.

Cliff notes: Have confidence in yourself. Do fun things and have interesting hobbies. Exercise to maintain health. In that order of importance. That's about it.