It misses details and elaboration, especially on the actual writing part. However, what can you expect for $3? It is a good start, nothing more, nothing less. If you get more into adventure writing you might leave some of it behind and explore the depths and possibilities of adventure writing that are out there. I for myself don't like writing adventures in the form of scenes. The scenes are something which happens in my game, not on the planning table. I have to be honest - the author implies that his guide is for GMs how want to play the adventure after they have written them. I do it the other way around, first I play the adventure, then I might bother to write it down for others, will the input and insights I gathered from playing. I think it is a waste of time to write adventures in this way befor you play them. Especially with that in mind the book doesn't get in the art of rewriting and redacting your adventure.
So, in the end I give a solid 3 out of 5. It won't change my game, but it wasn't a waste of time or money either. Maybe I will even try to write one of my next adventures exactly like it is recommended in the guide.
[3 of 5 Stars!]