This is a day trading book published back in the '90s. It is worthless, for a few reasons.
First, any day-trading book written in the 90's will be useless from a tactical standpoint since those day-trading strategies are based on technology which has changed (SOES, decimals, ECNs).
Second, the book makes day-trading look way too easy. It makes it look like you can just hit peoples bids and offers on Level II and quit your job. Some tactics - like "buying at the bid" - should never enter the beginning trader's consciousness.
Third, the book is way too technical for a beginner. Most concepts (like how market makers operate) will be over the head of beginners, some of whom have trouble understanding even basic concepts.
Fourth, it fails to point out the skills needed in becoming a successful day-trader. There is a misperception about day-trading that success is based more on having the right technological tools (exotic orders, ECNs, real-time quotes and charts), and less on having the softer skills of trading (i.e. market wisdom). The book does attempt to wade into this area ("Gauging the strength of the market"), but this section is embarrassingly brief.
Fifth, the skill of day trading - more than any other type or trading - is more about "doing" than "learning". This makes day-trading less susceptible to book-learning.
Don't read it, even for free.