Ask HN: A year to do my own thing – how should I prepare?

My partner has got an amazing job offer (for a year-ish) in an area that doesn't have many software engineering opportunities. I'd like to take that time to do something I've always wanted - start my own company, preferably building a SaaS product.

I have a full-time job now as a software engineer in the bay area. There's a year and three months before we leave California.

What can I do now to prepare? What skills should I learn? What books should I read? Has anyone here done this before and do you have any advice?