Best books on getting started with renewable energy and solar power?

I would start by learning the basics of electrical work via YouTube (books are available at home depot or lowes) and building electronics projects.

Assuming you are in the US, I would reference the National Electric Code (NEC). I think it's even available free online. This will go into detail about all the requirements for electrical systems to be safe and pass inspection.

If you are looking for DIY, there are some pretty solid channels on YouTube. I looked a few years back and it was impressive what they were doing then.

If not DIY, could you be more specific with the topic you are interested in?