They each consist of two wooden boards, with a folded scroll between them. They open from right to left, in the Chinese manner, so that they simulate pages.
At each double page, the left hand page is a picture, and the right a description, in Chinese and English.
Presumably, the Chinese text is good. The English appears to have been typeset by someone who has no English at all, though the meaning is usually fairly clear.
The text – both languages – has been printed on multiple sheets, and glued together. Sometimes, it is clear that the Chinese has been printed separately from the English, and glued in place. The pictures have been prepared separately on traditional paper with a silk grain in it.
The paintings are the the best features of these books. My guess is that the line drawings are printed using wood block, but, unlike Japanese prints (Hokusai, for example) which use multiple print runs with different woodblock masters in different colours, these appear to have been individually hand painted.
Click on the individual images for examples: