In my experience you don't need to know much about tax laws to run a small business. Find a cheap accountant* , and he'll tell you everything you need to know about taxes in two hours.
* When you are just starting out, it makes a difference if you pay someone 300€ a year to do your taxes, or if you have to pay 1000€. Stay away from the big companies. They will charge you for every phone call. Ask other small business owners for references.
Hiring an accountant was a godsend. I had just moved to a new city and did not know we had a business property tax here, or that the city itself had their own business licensing requirements (even for work-from-home freelancers). Not only did my accountant quickly get all of that taken care of, they also found more deductions in my taxes than I was paying them. It paid me money to hire an accountant.
Technically, yes, one could navigate all of the forms on their own and get even more tax savings, but that is only the case if you don't value your time. Since I charge my clients by the hour, and filing taxes often takes several hours for us in the United States, having an accountant also meant I could work without worry and make money instead of having to take a day off from working or stress myself out on my regular days off.
Hire an accountant. Do it right away, you give them a retainer and they'll have a price sheet of services they offer. They'll ask you what your goals are, just tell them you are interested in making sure you are in full compliance with the law, but don't know what you're doing. They deal with customers like us all the time. They have it streamlined and know exactly what to do.
* When you are just starting out, it makes a difference if you pay someone 300€ a year to do your taxes, or if you have to pay 1000€. Stay away from the big companies. They will charge you for every phone call. Ask other small business owners for references.