I have not dedicated much space to designing and building HTML forms here, simply because I consider it a fairly minor aspect of PHP. Handling those forms is important, though, and we will be doing lots more of that in future chapters. If you are looking for a good book on learning HTML more thoroughly, consider these:
Elizabeth Castro's HTML for the World Wide Web. This is a Quick Start guide so is full of pictures to help get you going as quickly as possible. This book is quite compact, and there is not all that much text, but at the end of the day HTML is a graphical system so this is not a problem.
More technical readers might want to consider HTML & XHTML: The Definitive Guide by Chuck Musciano and Bill Kennedy - it is longer, much more detailed, and really gets to the bottom of various topics that Castro's book just mentions in passing.