I used this book for a microcontroller assembly class in college last year where I had to program a 16F84 to activate and change intensity of some lights sources, controlled via RS232 with a PC interface. Overall, I guess the book was quite helpful, far from perfect, but it did make the job a lot easier. I somewhat agree with the other reviewer that the book is a big vague sometimes and that reading the programming datasheets available on Microchip's website is essential. The datasheets are extremely complete, but sometimes they are really useful only when you know what you're looking for and how it works. Basically, they are perfect for reference, but not enough when you're learning from scratch. The book also has some code bits, for very common uses like Loops, doing For and While cycles, Time Delays,Lookup tables, interrupts, etc. The amout of info covered in about 150 pages (including the usual command and register lists) is insufficient. I often found myself needing more details. This is definitely no PIC bible. The book is also very focused on programming and not really on the electronics. You get a few circuit diagrams, but not much. (to me this was good, since I had to deal only with the assembly and not really with circuit design).
Overall, it is a useful book, but incomplete and lacking better organization (not to mention the cheap and amateurish print look, but that doesn't really matter). It is worth reading if you're starting with PIC 16F84 assembly. Perhaps a bit overpriced for what it offers, but since some parts are very well explained and very clear, it is the perfect companion for the official Microchip Technology programming datasheets.