These help pages are the manual. They are set up such that you can print them in one complete set, but please think of the environment before doing so.
Checking Amazon, I see 10 books with LTspice in their title:

The books by Michio Shibuya, Gilles Brocard, and Mihail Pushkarev(book cover not illustrated above)are high quality. The graphic on the title page of this help document is due to Michio Shibuya.