I am a full time resident of one state. I went to visit a friend in another state and help him out as he was starting up a new business and needed some help, all the while maintaining my residence in my state, and while there did some nanny work for which I received a W2 with that states taxes withheld. Do I file my states tax return as full time resident and a non resident tax return for the other? Is this common? I do not relish getting audited, have never been and don't want to start now.

Yes, file tax returns for both states. You will have to pay taxes on the NR state income in your home state, but the home state should give you a credit for the taxes paid to the NR state.

Yes, this situation is quite common. Provide copies of the other state's tax return when you file (by mail). It answers questions before they are asked.

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