I'm basically in the same boat, so take my input with a grain of salt. That said, from what I've read, it's important to avoid, or at least be careful with, guides that focus on muscle training. There are exercises out there that can apparently be harmful and cause injury. When I get started in earnest, I'm planning to begin with TransVoiceLessons on YouTube. The girl in those videos frequently makes the point that nothing in voice training should be painful or cause strain, which sounds sensible and encouraging to me. Of course, there will be muscle memory training - it's muscle strength training that can be problematic.
That might be off topic to your actual question, but I wanted to throw it out there just in case.