I have been a SPICE user for a few years, but have never really known much about it beyond what it does. I needed to model a new device, and started looking for a program to do so. After i discovered the extreamly high cost, i decided to buy this book. The book is well laid out, with a nice focus on practical work. It doesn't talk about the general's of SPICE, so you may want to try his other book as well. However I found the book to be extreamly useful, and the book is well-written so I found that I didn't need another (intro to SPICE) book to figure out the syntax of SPICE. There are several examples you can study, so probably you could figure it out from them.
The only problem is that sometimes the author refers you to using expensive equipment to measure a real devics parameters. However you do not need this, and the book shows you how to get the required information off of a datasheet. The book's pretty expensive, but nice. Make sure you check out the sample chapters to decide if the books for you!