One of the biggest problems with having a personal library of paper books on how to write code for websites is that every few years they become obsolete. Accordingly, we no longer recommend paper books for learning how to code. For that, pick one of the many online services that will teach you how to build websites or do web programming, for free! Just Google it and you'll see how much stuff is available to learn online.
For more in-depth help on coding PHP, we recommend PHP.net.
Click this link to learn about the Bootstrap Platform, which has great explanations of the bits and pieces of Bootstrap; it is also where one downloads the various pieces of it. Also note, one can always ask Google for the answer to a coding question, usually Google does a yoeman's job of answering such questions quite helpfully.
To sort out how to make tricky code work, there's always Stack Overflow to answer your questions.
Disclaimer: If you buy books through our links to Amazon we'll make a small commission on your purchase. Note that we don't recommend books unless they've actually helped us.