In the US, being a freelancer, you are considered self-employed and there are certain tax forms to go along with that status. These can change from state to state.
When you decide that you are your own business, employee of one, you have a few options. If you're in Washington State, this is a brilliant resource for figuring out where you stand and what kind of taxes you probably need to file.
As a single employee, you'll probably fall into Sole Proprietorship or LLC (definitions here). The nice thing about an LLC is that if you get sued, only your business assets can be attacked. In a Sole Proprietorship, everything is fair game.
I'm going to level with you though. How likely are you to be sued? If you're just publishing your own books, which used only your own content... not likely. But it's something to keep in mind as you rise in the ranks of notoriety.
"Do I really need to run out and register a business right now?" I here you asking. The reality is... no. You don't. Likely printing up your first book, it will be a short run, and the income gained won't even require filing taxes for it. So play around! Try stuff out. Then, when you decide to move forward with becoming a business, you can apply for a license.
I do encourage you to act as if you are a real, live business whether registered or not. It's the "fake it 'til you make it" idea. The more legitimate you act, the more highly you'll be regarded, registered or not!
Tomorrow's topic: Do you need an editor?
Until then, are there any topics you'd like to cover? Questions about publishing you want answered? Let me know in the comments!