This book helped me get into ggobi, which is what I bought it for. Two main obstacles for new ggobi users are its peculiar user interface and awkward input of data. The latter issue is solved by the R package rggobi, which can use R data frames directly. The user interface is marginally better with rggobi; you can script the basic creation of figures, selection of datapoints, and choice of focal variables. The whole thing is still rather awkward, though: For example, to change views or interaction modes, you need to leave the figure window and visit the main ggobi window. While it is possible to change formatting (glyphs, colours, sizes) it is very difficult to figure out. The book is almost indispensable in taking you through the rather unintuitive workflow of (r)ggobi. The book also has OK introductions on classification and clustering. All in all it served its purpose, but I probably won't be coming back to it.
Users looking for an alternative might try the R package iplots, which has a somewhat smoother user interface; I ended up using both.