OK so I will just mention three things that are important.

1. Be well groomed.  Hair cut regularly, shower regularly, shave, etc.  Don't be afraid to wear a bit of face powder to cover up acne or other blemishes.  If you are having trouble with clothing style, then ask a female relative like a sister to help you pick clothes.  Trust me they love to play dress up and will be all over that.  Be sure to pick someone your age, you dont want to dress like a teenager.

2. Confidence.  This is very important.  It is a myth that you have to have money to get a girl.  It helps but is not the number one factor.  Stand up straight.  Good posture is key here.  To develop confidence when speaking to women what you need to do is actually just talk to more people.  Go up to strangers in the grocery store, book store, or anywhere in public and just say hi.  It will be hard at first.  Just fucking do it.  You need to be positive and smile when you talk.  You need to be positive because no one wants to be around negative people.  What I mean is, lets say a friend gets a new watch or car or something.  A negative person would say "woah he spent way too much on that crap.  He must be compensating for something."  A positive person would say "hey nice watch dude, it looks awesome."  Do this every day.  Make it a goal to talk to at least three strangers a day.  It does not have to be a full blown conversation, even saying hi is a good start.  And it doesn't have to be an attractive woman.  Men count too. It is hard to talk to strangers so this will help you build confidence.  Employees or other people that have to talk to you as part of their job do not count.  If you don't go out into public much, the get your ass out there every day.  You will meet more people.  You can also look at websites like meetup.com to find activities you enjoy with others.  I recently started rock climbing, and women like doing that too.  Its not just about meeting women though, if you get a larger social circle you will naturally meet more people.  Married people (especially women) love to set up their single friends.  So increase the size of your social circle and you will meet women as a part of the deal.

3. Exercise.  You should exercise daily.  Cardio such as jogging is a must.  You dont need a gym membership, just spend an hour a day jogging, doing pushups, etc.  There are plenty of great workouts online.  You will look better and feel better.  Plus it will boost your testosterone a bit and make you feel more confident.  You can also take up a sport you are interested in or a martial art.  Judo and Brazillain Ju Jitsu are great because they offer an excellent workout and you don't have to get punched in the face.  Don't skip this one.  It is a pain in the ass to work out every day, but make the time for it.  You won't regret it trust me (after you get over the initial hump of being sore all the time that is).

Best of luck, once you get started you will have fun, and find that it is not as hard as you think it is.  Don't worry about the rest, it will fall into place when you meet a woman and click with her.