Being an appraiser can help your real estate investing business enormously. It's also a fantastic career, if you can get into it. And that's the problem; the insurmountable problem facing anyone interested in becoming an appraiser today.
Unfortunately, it is (for all intents and purposes) completely and totally impossible to become an appraiser. The way one would become an appraiser is to take, depending on your state, 75 to 80 hours of pre licensing education, pass a couple of super easy tests and then you'll need to find a certified residential appraiser willing to take you on for at least six months, usually it's two or three years, in order to gain the required work experience hours.
The problem is finding a certified residential appraiser willing to bring you on as a trainee. unfortunately, appraisers have absolutely no incentive whatsoever to bring on new trainees. Training someone new takes a lot of time, a bit of money, and can create a lot of stress. It's not worth it.
The primary governing body of the real estate appraisal business is the appraisal foundation and the appraisal qualifications board. Both of these institutions are totally useless to existing appraisers and have done nothing but damage the process by which new people become certified appraisers.
So while it is a very good idea to become a real estate appraiser part time, I would simply remove this option entirely.
In retrospect, I should have personally gone the home inspection route...