http://www.wikihow.com/Be-a-Rocker
Learn. Consider taking a few voice lessons or buying a guitar, bass, keyboard or a drum set and take lessons. Try to find a few friends who play an instrument, (typical rock n' roll instruments are drums, electric guitar, electric bass, vocals, and keyboards), and try to form a band, write some music and practice!
2. Be yourself. All the rockers aren't acting like someone they're not.
3. Get band tees of your favorite rock groups, old and new. Also, get some shirts of slogan or ads or just plain tees and maybe some tees of concert venues. Plus, you can never go wrong with a good old Jack Daniels T-shirt. Anything with skulls isn't necessarily rocker. Striped thermals are also very rocker. Black/Gray and Black/White stripes are best though.
4. Wear baggy pants or tight pants. It doesn’t matter. It's your preference. Bondage also works. If you're going with baggy, camo is a good choice along with black jeans. With tight, leather, black, or blue jeans will work well. Make sure you have some holes in those jeans!
5. Jackets add a great touch to your look. Black leather jackets are always perfect. No need to spend any big money though, you can get a much cheaper leather jacket at your local motorcycle supply shop that is of the same quality and will probably last longer. A solid color hoodie (black, gray, etc.) would be another good choice, along with striped hoodies (black/gray or black/white). Denim jackets are good too.
6. Choose a hairstyle. Long hair (the longer the better), short hair, medium, and buzzed are all fine. Emo hair is obviously not rocker hair, although remember to be yourself. (NOTE: A Beatles cut is not necessarily emo)
7. Get some shoes. Converse, Vans, combat boots, boots, or even white trainers, it really doesn't matter. Avoid Jockey or New Balance shoes, however.
8. Accessories are essential for the rocker look. Spiked and studded wristbands are a must. Rings are also good, with silver rings or with skulls or tribal patterns, it's good to wear them in excess on your hands. But with gold, be careful! You don't want to be mistaken for Flava-Flav do you? If you decide to wear sunglasses, don't spend too much, you may end up losing them anyway. Good choices include Aviator and Wayfarer design.
9. Hats can be a nice touch. Bandannas, top hats, fedoras, skull caps, or even the simple baseball caps are all acceptable, (just look at Tom Morello, for example).
10. Cool tees are a must. But don't just get any tee, get ones that are "you"