Form 8822 is used to notify the IRS of change of address.
If you and your wife have been filing a joint return, I do not believe you need to file an 8822 unless you have moved.
The revenue and expenses that you earn from your artwork will be reported on Schedule C which will be part of the Form 1040 that you and your wife file.
You will need to keep track of your profit (best practice is to keep track monthly) and make estimated tax payments.
Remember, the Self-Employment Tax (the social security and Medicare taxes on your art work profit) is 15.3% of your profit.
