In all of the discussion and taking a closer look at your post, it occurred to me that some of the most obvious and important parts of your post have been ignored.
First off, you state that you have book one, that it only has line drawings, and is mostly written text. It is book TWO that actually has the music in it. Book TWO is where all the work is. Book ONE serves as sort of a teacher for book two. Both books are to be used together. In fact, I have many of my students purchase only book TWO because they are taking lessons. In addition, there is a book THREE that is ALSO to be used with the other two books. Especially if you are going to do this without a teacher, I HIGHLY recommend getting all three books. At a minimum, you will need book two in order to begin.
Secondly, you asked about "Precede each movement you make on the guitar with a clear aim." Yes, this is very specific, not general at all. While it takes a lifetime to fully understand (I am still figuring it out...lol) the premise that holds all of this together is very simple to understand. I will spell it out very explicitly:
We are creatures of habit. For better or worse, when we repeat something over and over, we get very good at it. What that usually means is that we get very good with making the exact same mistakes over and over again. We get very good at those mistakes because we repeat them over and over. Something happens almost immediately with all students. If it doesn't happen the first week of study, it happens the second week of study. Perhaps it is in one of the first So-Re exercises, or perhaps it is Bugler's Tune. It might not even happen until the middle of Lullaby, but it WILL happen: a student will not readily be able to play what is written on the page with out a mistake. Attempting to play it over and over is not the solution. Remember, for better or worse? Creatures of habit? Sure, a student may eventually get it, but that isn't the point. The "play it over and over" method is the complete opposite of what needs to happen. Without dealing with this sooner rather than later, a student is sure to quickly begin hitting a wall.
The first time a student can not readily play what is written is a crucial and wonderful moment with the teacher and student. It is an introduction to what I spend most of my time doing every single day, and is the very beginning of learning to work efficiently and effectively. So, if you don't repeat the piece over and over, what do you do?
You find the problem. If there is more than one problem, you focus on one problem only. You set everything else aside. For example, you play a quarter note instead of an eight note in one spot. As a result, you come in too early for the next note. Being a creature of habit, you are likely to repeat this mistake. So you take a very small section of music that ONLY CONTAINS THAT ONE PROBLEM AND NO OTHERS. Slowly and carefully, you make sure you understand what you were supposed to do, but didn't do. You can even sing it, or play it with your air guitar. You erase all the other music from your attention and quickly discover how easy this isolated passage is if you only had to just play it and could also play it very slowly.
So, that is exactly what you do. You carefully and slowly play the passage correctly. Avoid the temptation to speed it up. Remember, you are trying to build a new habit. You want to go slow enough that your mind is ahead of the fingers. You know that what you are about to play is correct before you even play it. Through repetition, you will get very good at it.
Now, think about it again in THAT context. Read again Shearer's Guidelines for study and practice. Those guidelines serve me every single day when I am in the practice chair. And a good deal of my time is spent every single week with every single student getting better at it. What I tell my students is that we basically cheat. It is like we have found a loophole. "Wait a minute, let me get this straight. So, no matter what I do, if I repeat it, then I get very good at it! Ha! I'm going to beat the system! I'm going to take small enough sections, and play them slow enough so that everything is very contrived. Each little snippet will be so easy and simple that I won't hardly ever make a mistake. And I will just repeat them. And then, I will gradually put the sections together and accidentally get good! Haha!" Yeah, that is kind of what we do. Or at least it is kind of what we SHOULD do. I'm getting better at it, but I'm not there yet!
Get that second book and start learning some music!
Dr. Todd Tipton, classical guitarist
Cincinnati, OH, USA (available via Skype)