What books or resources are best to learn how to build and launch amateur rockets?

It depends on where you are starting from. Starting from scratch, there is a lot of basic information in "The Handbook of Model Rocketry". It is specifically aimed at model rockets rather than amateur but the basic subsonic aerodynamics are not going to change much. There is a thriving high-power rocketry community making and flying rockets that are heavier and higher power than traditional model rockets. A lot of the upgrades in the building methods for high power would be applicable to  full-on amateur rocketry. They (Through the National Association of Rocketry and the Tripoli Rocketry Association) also have a handle on a lot of the regulatory issues, including FAA waivers for flights and the propellant handling and storage requirements that come out of ATF. There are still people working with designing and building their own engines but that is relatively uncommon since for safety reasons both model and high-power rocketry have moved toward commercially-built engines for safety reasons. Most of what you see are commercially made composite engines, but of course, somebody has to make them and a number of the companies making them are relatively small.

As previously mentioned: The "Handbook of Model Rocketry" by G. Harry Stine (now in its 7th edition) is a good place to start for "low power" rocketry. If you'd like to move on to something a little more powerful, a little more experimental, and a lot more "hands on"-- I would recommend "I Still Have All My Fingers - How to Build a Big Sugar Rocket on a Budget Without Losing a Limb" by Dan Pollino.