Resources to learn about software development (life cycle)

So I think I'm close to getting a job that's somewhat of a project manager position at a tech company that mostly creates websites and mobile apps. I know little-to-nothing about software development, but the company is open to me learning about it while on the job.

I won't be doing any coding or actual front/back-end development, but as a project manager in this (agile) environment, what are some main things that I need to know about software development and the SDLC? And besides google, what other resources (books, websites, videos, etc.) would be helpful for me to ramp up my knowledge in this area?