Made it through the first two video chapters and will certainly finish later on.
For a lot of similar material in coffeetable book format, there is a concept art book; searching around suggests that it is "Half-Life 2: Raising the Bar". My beloved copy is buried somewhere deep in storage, but it is a prized possession.
E: Turns out this book has gotten pretty rare, and a re-print with added content was announced as part of all of these updates.
