ARRL Antenna Book
If you are looking for an incredibly thorough antenna reference, the ARRL publishes one of those too, the ARRL Antenna Book: The Ultimate Reference for Amateur Radio Antennas, Transmission Lines, and Propagation. It’s very comprehensive (as its long title would indicate) and I’m not aware of anything more detailed or thorough when it comes to understanding antennas of many types. It describes almost any kind of antenna you can imagine (and probably many you wouldn’t), with building guides and specifications for many types of antenna projects.
