Which country/state are you in ? If in the United States, I recommend finding a good local accountant/CPA who can help. Usually, for any projects that hopefully bring in revenues, you will need a good accountant to help with taxes etc on a recurring basis. Better to find a good one upfront and then work with them.

The problem with using generic services is that they may work fine in the beginning but you may end up contacting an accountant anyway for best advice on tax and planning. Yes, even for side projects that bring in some money.