The text is written in a pleasant format punctuated with relevant comments. The topic is Windows 98 from an end-user view point: it is a cross between "Popular Computing" and Cisco & Ebert. Even the frequent characterizations of Bill Gates ("Billie") and the two short, heavy-set guys (Leonhard & Simon) are tasteful and instructive.
If you want to learn about using Microsoft Windows 98 with some good inside tricks, this text is a good beginning.
If you want to know the API function calls to write programs for Windows 98, you won't find what you need here. In fact, the book reads so nicely that you will probably need to fight to keep focused on your work, instead of propping your feet up on your desk and enjoying this light read.