This was my textbook for my Information Literacy Instruction: Theory & Practice. Out of all the textbooks for librarianship that I had to read this one is the best.
Wong & Saunders are concise and to the point. Their textbook is not necessarily wordy. It is written in simple English so anyone can understand it. The organization of this book is perfect. Plethora of examples and infographics.
Best of all this, textbook is also an open source. If you cannot afford it as an actual book you can just download the PDF for free.
This is a very informative open access book on information literacy instruction. It mainly focuses on academic libraries, but discusses public and school libraries too. The style is conversational and easy to read.
More depth on theories and concepts for instructional design. Good for foundational start for those doing or planning to do a lot of instruction in libraries.