You may have begun to write… or not. But you know there’s a book in your future. These are just a few quick and dirty things to do. If you end up with a book in hand, you’ll be happy these things were done. If that book never materializes, there is no harm done.
Open a savings account that is only for your book. Doesn’t need to be a business account, just a plain savings account. Put any money that you get toward writing (donations, sales, etc.) into this account.
Keep track of all income and expenses. I use MS Money – it’s easy to use and it’s free to download.
Get a state tax ID number. If you decide to self publish, then use your publishing company name. If you don’t self publish then use your author name. Do a search online for your state and “tax ID application” to find out how to do it online.