Reddit mentions of How Patterns Work: The Fundamental Principles of Pattern Making and Sewing in Fashion Design

I'm not familiar with the Lo book, so I can't say. Read the reviews. You will find that every pattern making book has similarities and differences. I'm taking a pattern making class now taught by a professional pattern maker and while some aspects are quite familiar I can't use a book as a reference because her method differs in certain respects and if I followed a book it would throw me off. I hope that after the end of the class I'll be able to use any book. But it is important to understand one method first, and there are lots of subtleties that I would have missed but for having taken a class. I showed the teacher a sloper book I own but never used and she said it was good. It has a companion book for developing patterns, but she liked the sloper book better.

Getting the sloper right is essential. It's the foundation for the patterns you develop from it. In my once-a-week basic class, we spent about five weeks measuring the form, drafting the back and front bodice and skirt slopers and the sleeve sloper, fitting, correcting, re-fitting, etc. It's a big class and first the teacher does a demonstration but my point is you shouldn't think that you should be able to bang out a perfectly fitting sloper in two hours.

We next did dart manipulation exercises using the pivot and slash and spread methods, then princess style line conversions, then facings. Now we're doing collars.

Most methods use letters to refer to points. They are completely arbitrary: Point "J" in one system is not going to be the same point in another.

If you're interested in pattern making, I recommend Kathleen Fasanella's Fashion-Incubator blog. She's a pattern maker who advises small sewing businesses and bought a small factory. Here's a post in which she explains how she reviews pattern making books.

For a high-level introduction, you might want to read How Patterns Work. It's more the general theory of pattern making, not the nitty-gritty of how to true lines.

I bought this book a while ago and have never used it. I've read it's not that good because the author does not have formal pattern making training.

If it were I and taking a class was impossible, I would try the University of Fashion videos on pattern making. There's a free trial video on drafting a straight sleeve sloper. The tools are listed, every step is shown, and there's a transcript on the site. I think the method shown is very clear and it's similar to others I've seen but it wasn't the method my teacher used. For one thing, we didn't use a chart with standard measurements: we took the measurements from the armscye (armhole) of the drafted bodice. Our elbow line measurement was taken from the waist of our bodice because the elbow of a well-proportioned person falls at the waist. We drew a center line with an L square as a starting point, not a fold. Just these three little things can result in a different sleeve, which is why it's important to use a consistent method at least until you have a lot of experience and understand which parts are transferrable.

You might find How Patterns Work useful. It's not a drafting book.