The trouble is that things change too quickly for there to be a specific tome that everyone agrees is gospel. I think the closest you will get to gospel in this space are classic books like K&R C, which have very little to do with Linux per se.<p>Also, a "book on linux" is going to look very different if it's based on Debian as opposed to e.g. NixOS. Linux distros come in all shapes and sizes and no matter what level you're operating on (just using the GUI, light sysadmin, deep systems programming, down to kernel hacking), they may appear as totally different paradigms.<p>I would recommend simply daily driving Linux. If you're still using another operating system, ween yourself off of that. Additionally, there are a bunch of obvious projects that are low hanging fruit for just getting to grips with Linux. Want a personal website? Spin up a VPS or a cheap laptop and build it from scratch. Set up your own personal email. Get certbot running. Write a simple server in C that can do request/response of TCP. Write an i2c driver for some random micro you have lying around. Whatever you are interested in making/doing, just go do it.<p>Resist the urge to google everything. `man` has more information than you think it does.