First of all,,, go for it.
secondly, as in any "business" you need to get your legal needs taken care of.
I recommend a simple DBA be filed at your local court house. Then, open a checking account in the name of the business. This will establish you as a business, and will facilitate keeping your business records seperate from your personal life.
Thirdly, make sure you keep good records. i.e. inventory your equipment, record your expenses, record your income. If you treat your business like it is a big deal, you will be much happier when it comes time to do taxes, etc.
You will need some vehicle to market your photos. Stock agencies are OK, but there are a bunch of them, and finding the one that is best for you can be a full time job. Often, the best ones have very strict submission requirements that eliminate a lot of photographers.
You will need some way to sell photos to the bikers, etc. Again there are many out there. I use
www.exposuremanager.com and am very pleased with them.
If you keep your expectations low, you will enjoy turning your hobby into a money maker.