Nice find TA.
I've done some formal logic. What I did used some different words and systems to those found in the book, but from what I see here they are essentially equivalent.
I did not complete the class, but what I did complete I was in the top percentile. What I'm saying is I'm good at what I know, but there's stuff I don't know.
Tips and trivia:
1) - Logic is a skill. It's learned. It's far less innate than many would have you believe. If you are struggling at the start it's still very possible to do well by the end. You need to practice it like it's an instrument though.
2) - It's something you learn systematically. Everything you've learned seems easy, while everything you've yet to learn seems impossible. I strongly disagree with TA's view that is should not be difficult to understand, and everything I've read points in the other direction. Most people are bad at logic to begin with. It's difficult, then it's not.
3) - The guy doesn't seem to be writing to an unexperienced audience. Have a dictionary handy and don't let any word escape your grasp. Logicians tend to be good at articulating precisely, but logic =/= communication, and often the emphasis that the reader is looking for isn't present. Don't read on until you understand everything entirely, unless you're definitely coming back.
4) - If possible, practice at every turn in every day life. If you disagree with someone, articulate it on paper in whatever logic language you're using.
5) - This is more of a general hint for study, but I found it particularly useful with logic. Try to come up with ways to process spatially. What would this looks like in a truth table? A truth tree? What categorisations can be used to order the X different fallacies/proofing methods/symbols etcetc?