Photography is a mixture of Artistic Ability and Technical Skill -- the magic of the mix isn't written in stone. The world is filled with technically proficient but artistically uninspired photographers, there seem to be a smaller number of artistically gifted but technically unsavvy artists, but they're out there as well. But the most successful people have a mixture of both -- they have an artistic vision, and they posses the technical skills to know how to make that a reality. The technical skills are the easy part, you can learn them from a book -- f-stops and shutter speeds and light modifiers, etc. The difficult thing to come up with is an idea.
0) Possibly the most important thing of all: Find creative people and make them part of your world. They don't have to be photographers. They can be writers, or musicians, or actors or puppet makers. Have a peer group of people who are doing things. They'll be your inspiration, your facilitators, your idea makers, your artistic partners. Do this for the rest of your life. Artists rarely survive in a vacuum.
1) Get a camera. It doesn't matter what kind. Eventually you'll most likely end up with a Digital SLR but in the meantime a point and shoot, your cell phone, a 1946 Brownie Box Camera, all these will work to start out.
2) Study photography -- this doesn't mean go to school for photography, but it means pay attention to photographs tear photos that you like out of magazines and keep them in a scrap book, get photography books from the library, from the bookstore, at yard sales. Learn what types of photography you like. Landscapes? People? Bands? Artificially lit? This will start to provide you with your visual vocabulary -- which will be important in figuring out what you want to photograph. Given a camera many new photographers are left baffled as to what they ought to be taking photos of. Subscribe to photography magazines, fashion magazines, travel magazines.
3) Take photos. What is it you're interested in? Enlist friends. Take trips, set up elaborate hoaxes, copy great works of art, copy not so great works of art.
4) Make a portfolio of your 12 best photos. these can be 4x6 1 hour prints. Every month try and replace at least one of these with a better photo. Do this for the rest of your life.
5) Evaluate your equipment. When you know specifically why what you have can't do what you want, it's time to think about upgrading. Do this for the rest of your life.
6) Find someone who will pay you to take photographs. It's always easier to learn on someone elses dime. It doesn't matter what the job is -- assistant to another photographer, part time local newspaper, photographing houses for a Realtor, etc.
7) Go to school. You can learn a lot more quickly this way. Things like advanced lighting techniques, gallery framing, etc. can be more quickly figured out in an environment like this.
8) Show your work. It doesn't have to be in a traditional gallery, it can be in your parents garage, or in your stairwell. Some friends and I used to have an open-air art gallery we called "Show up and Show" where we'd meet along a length of chain link fence, hang out photos up and stand around and talk to passers by.
9) Take lots of photos, throw out the bad ones, only ever show people your best. Do this for the rest of your life.
10) Stay busy. The opposite of busy is bored. Don't visit that place. Do this for the rest of your life.
Hope this helps.