This is slightly embarrassing. I'm a professional developer working at one of the big tech companies and I've never used a database. I've got an idea for a website I want to build as a learning experience and possibly as a business, but I don't have the faintest idea what database to use, let alone how to fix/debug the database when I run into problems.
I'm looking for a course, a website, a book, etc., that will give me an overview of modern database technology (SQL vs. NOSQL vs. relational vs. non-relational (I only have a vague idea what these even mean)). I'm starting by googling/wikipediaing all of these terms, but if there are better, comprehensive resources available that I should be aware of, I'd love to hear about them.