There may be readings for each session, but they are not readings for memorization. Lectures will not necessarily follow the readings, and they might not even touch on all of the content in the readings. The purpose of the readings is to provide you a context within which to experience the lectures and exercises that follow. You will want to do the readings to have a framework within which to work.
This book is available for free to UNC students through Safari Books Online, and it is a good reference tool.
If you feel that you want to have an HTML reference book, you may wish to purchase Duckett, J. (2011). HTML & CSS: Design and build websites. Indianapolis, IN: Wiley.
You can survive without this book, but if you prefer a physical book, you would be well advised to purchase it and use it extensively.
These will include links to a variety of additional resources, to more fully explain or expand on topics discussed in the notes. Some of the linked sources may include:
online documentation from UNC's Information Technology Services (especially the help link), other information sources available via the Web, or readings that will be sent to you as email attachments or as blog posts.
Pay attention to the schedule and to the class blog. Session notes will be posted prior to each class and you would do well to look over the links prior to coming to class. If there is something that you should read prior to class, it will be included on the session notes for the session prior to the class you will be preparing for.