Like Gamma G and Monica, I know three people that started doing taxes. One does personal taxes seasonally in the evening and makes quite a lot of money in the span of 4 months. You can generally choose your availability hours to suit you needs.
One started doing it full time, including business and non-profits and enjoys it. The last one only did one season because it just wasn't her forte.
I can tell you that regulations changed last year. You will be required to take short-term online classes (as usual) but the material is expanded from past years. Testing is also now done in person at secured and controlled sites, much like SAT/ACT testing, but with stricter rules. The seasonal worker I mentioned was really nervous about it, but everything was fine.
Another option some of my friends have pursued is working for the school that their children attend. Some are aides, substitute teachers, or other positions depending on their qualifications.