Fair use: Instructor sharing notes from textbooks I am a new instructor, planning a course; this post comes from good faith. Basically, I am designing a course and am trying to give my students the best learning outcomes without demanding that they spend too much on textbooks. 

1) There is one main textbook that I want to assign: Textbook A. From textbook A, I want to make my own detailed notes (certainly not word for word) so that my students can mostly read the notes to learn. From the student's perspective, the textbook is mostly for occasional reference and for the homework exercises. If I list this book on the syllabus and "demand" that students buy it, am I free to write my own notes without dropping a citation every other line? Can I post these on the course web page online?

2) There is another book, Textbook B, that I like a lot. Due to the fact that I don't want my students to pay an absurdly high fee for two textbooks, I do not wish to demand that my students buy it. However, I do want to occasionally reference it for my own purposes. Is it sufficient to list it on the syllabus as a book that I am referencing, but explicitly state that it is not required for purchase? Again, the plan would not be word for word copying or anything -- just for some ideas, possibly even coming up with reworded versions of homework or exam questions, etc.

I am torn on these questions. A part of me feels like I could do something wrong, but I also know the copyright laws seem to be pretty relaxed when it comes to teaching.

The "treat others the way you want to be treated" rule makes me believe that ethically, textbook A is fine, and textbook B is fine as long as I (a) do not use it that much and (b) reference it for any notably clever ideas.

EDIT: To add to questions above: Say Book B has many real world examples (with citations within the questions). One of the main reasons why I like the book is the abundance of real world problems. But I like the flow of text A more for teaching. I would like to give many of the examples from book B, but again, I don't want my students to pay an absurd amount for a book that I am only taking questions from. How do I settle this? I certainly can't reword the problems using the original citations given in book B.

In summary: Like the flow of book A more, but like many of the real world questions in B. What would you recommend in order to reduce textbook costs?
I think you mostly are in the clear from an ethical/plagiarism perspective. Making your own notes off of a course textbook is perfectly acceptable as long as you appropriately reference the textbook. You can write a broad attribution in the beginning: these notes are largely based on the material in chapter X of textbook A. If you’re planning to take questions from a book but not more it’s fine to just reference the book for any specific questions you took from there, and list it as additional material.