Take introductory courses in French at school or, if you're an adult, enroll at a community college or use computer software. One of the benefits of learning from a live teacher is that you get feedback and you can practice speaking with your classmates.
Rent and watch French films. You can pick up by listening, and the more you watch, the easier it will be for you to sharpen your ear.
Practice speaking with a friend. Either meet someone at your class or post a classified advertisement online on a site such as Craigslist. You must speak, and speak often, if you hope to become fluent.
Practice and study as much as possible. Make vocabulary lists and learn how all the French verb tenses are conjugated. Spend at least an hour a day practicing on your own.
Go to a country where French is spoken once you have a foundation. Some international schools offer intensive programs through which you can live with a host family and study at a local university. Immerse yourself in the language while there and try not to speak any English at all. Although France is the obvious choice, it may be more economical to go to Quebec, where French is spoken. Other options include Switzerland and some African countries such as the Ivory Coast and Senegal.
Never be afraid to try. If you're not actually speaking, you're not becoming fluent. Recognize it can take years to attain a level of fluency. Just keep practicing.