Best thing I did for my writing and editing business was to hire an accountant. It took me a while (like more than two years!) to do so. No good reason why, but lots of silly reasons why not.
As a small business owner, I can't claim I was happy about mailing in my quarterly taxes today. I can claim, however, that having some fiscal structure to my business feels good. Sometimes I'm asked about how to start a small business. One piece of advice I am going to emphasize is hiring an accountant. Having administrative tasks like this taken care of clears the decks and allows me to focus on what I do best, which is not accounting.