I'm new to Linux and I didn't know about LFS. Thanks for sharing your experience, guys!

The same ones it takes to get one to Carnegie Hall: practice, practice, practice. Back in my early UNIX days (see below), I made a project for myself and then figured out what I needed to learn and know in order to see it through. There's nothing like jumping into the deep end. Of course, before jumping in the deep end, it's good to know the basics of swimming, er, backing up your important files. Just in case.

It seems like maybe you're already past where I would normally encounter a newbie. Back in the day, when I got fresh student interns to work on my projects, I'd sit them down with a couple of manuals and have then read certain material before turning them loose. First and foremost was becoming proficient with the system's text editors---they were going to be writing/maintaining code for the projects. With Linux, you used to be able to find books like "UNIX Unleashed" or "Linux Unleashed" at the chain bookstores that were invaluable for picking up general knowledge/theory about how the operating system did things. There aren't as many of those type of books in the stores nowadays but they do exist. They have largely been replaced by the Web so learning how to search for HOWTOs and the like is likely the best/cheapest way to find that knowledge. Asking questions on forums (hopefully, after some time lurking to learn the "rules") still works. Eric Raymond's and Rick Moen's article "How to Ask Questions the Smart Way" is still a good thing to read before posting things on web fora. It'll reduce the number of "RTFM" replies you'll receive.

I started using *ix back when I wanted to start learning C. C compilers for my Win386 box cost a lot at the time. Byte magazine (or maybe another one) had an article and an ad for a UNIX clone (Coherent) that looked interesting. An entire UNIX operating system -- C compiler included -- that cost less than a quarter of what most vendors wanted just for the C compiler. I found a way to transport all the FORTRAN code I was using on the VMS clusters at work and learned C by translating all that code into C. Later, I wound up dropping a bundle for a commercial UNIX to run on a homebrew '486 system. A couple of years later word of this "Linux" thing started making the rounds on Usenet. Again, it was cost that got me interested---an entire operating system + programming environment for next to nothing. (The commercial UNIX vendor wanted $700-$800 for the X11 development libraries.) While I consider myself a (fairly) early Linux adopter, even after all that time I still do not consider myself a "Linux bad*$$"---well, except in certain areas. To this day I'll still encounter something about Linux that makes me feel more like a "Linux blithering idiot". :^)

HTH and good luck. You're going to have fun.

If you have sysvinit as your init system, you can learn a lot about shell scripting by going through the startup scripts of your system step by step. I remember doing that in my early days with Linux. Doesn't work with systemd unfortunately!