Subtitle: The Official Hitchhiker's Guide to the Galaxy Companion.
This was written in 1988, after So Long and Thanks for All the Fish, but before Mostly Harmless, and long before Adams died.
I can't find an ordered list of Gaiman's works all that quickly, but this one feels a tad off. Perhaps it was an early work, or maybe he just didn't take it all that seriously. Regardless, it doesn't feel like he put a lot of effort into it.
That said, there is still some good info in here for Hitchhiker's fans everywhere. I learned a few things, and seeing some of Adams's wit on display again was good. I need to acquire the BBC radio series, though, and listen to them. Believe it or not I haven't done that yet.
As always, I miss Douglas Adams. A lot.