Books

Design with PIC Microcontrollers by John B. Peatman. Amazon.com
Good book, worth buying used. Compact and to the point.

Making PIC Microcontroller Instruments and Controllers by Harprit Sandhu. Amazon.com
Do not recommend, even for free. The title is enticing, but what is NOT mentioned on the front or back (surprise in Chapter 4) is that it uses a BASIC compiler by MicroEngineering Labs. If you want to understand how the chip works, this isn’t the book – a compiler is designed to isolate you from the bits-and-such. I’d never heard of this compiler before now (I’d probably go with C before BASIC).