I started a high-level document on LLVM some years ago. Today, it is maintained by Michael Rodler on Github. This document exists as a readable online book on Read The Docs. We are always looking for contributors. The idea behind the book is that we eventually want to document how to implement all/most high-level language features in LLVM, but I have to say that little has happened in this regard the last few years.
I have recent experience in LLVM as I am using it as the back-end in my initial bootstrap compiler being written in Python v3.7+.
Overall, I like LLVM a lot, but the Windows support seems to be lacking in the sense that you have to install Microsoft Visual Studio (which I personally loathe, I use the SlickEdit editor for all my projects) and sometimes the documentation is a bit lacking.
However, you can almost always get great examples by implementing your sample code in C or C++ and running it through Clang, the LLVM C++ Compiler, and then examine the generated LLVM IR.
I am no expert on LLVM, seriously, but I’ll be glad to help out if there is anything I can help with.