Some of the information here, such as what the "current" market is doing, is out of date. However, the middle sections were Koontz gets into the nuts and bolts of writing a novel, are extremely valuable to the new writer. He talks about plot and structure, dialogue tags, and researching places you've never been, among other things. He writes in a clear, precise manner that is easy to understand and I appreciated how he worded a few things.
On top of all this, he lists 99 authors he recommends and talks about a few of their titles he especially likes, many of whom are well known, like Robert Heinlein and Dashiell Hammett.
The sucky part about this book is that it is out of print and used copies can run from $150-$400+, likely because collectors of Koontz's work have driven the price up over the years. He's been saying he'll write a newer edition for awhile now, but I've not seen any indication that one is on the horizon. If it ever does happen though, rest assured, I'll be the first person waiting in line for it.