It's the first time this has ever happened to me in 30 years, and it's not something I'm proud of, but I was fired from a great job that I'd held for 31 days because I was trying to help a client. As a technical support representative for an e-commerce company, I wasn't supposed to import a client's data into their store, but the client asked me to help, and when I did, I damaged his store's existing data (hence the prohibition on importing client data), and I was unfortunately yet understandably let go.

Since I had only been there a month, and I'm forced to once again job hunt, I'd like to know your opinions on what I should do next:

1. Should I include this job on my resume?
2. If so, how should I answer when asked why I only worked there one month?

I don't have it in me to lie about the company, because I was in the wrong and because the company really was a great place to work. I kick myself every day that I totally blew a great job, but I still have to find my next paycheck, regardless.

I'd appreciate any insights you could offer.

Since it was for such a short time, I wouldn't put it on my resume, but then there will come a time (maybe at the interview) when you will be asked if you have ever been disciplined or fired. You'll need to figure out what to do about that. I suggest you be honest rather than have them find out some other way. Hmmmm, that's a tough one.

I would just not post it on the resume

I was told (about 40 years ago) by someone at a job agency that they are taught to expect most resumes to be untruthful and even salaries to be 10% higher than they really were.
I have lied in small ways on all my resumes. I also tailored each one to the job I was applying for.
I was fired from one of my very first jobs as a young adult. I never mentioned it.
I wasn't likely to ever be fired again, and I wasn't, in 45 more years.