Not a simple question to answer. Part of what determines a "good" book is your level of expertise compared to the author's level of expertise. The book needs to offer information that is new to you in a way that you can easily understand.
Many financial books are written by journalists hoping to make a quick buck ("The super secret way to day-trade for a living" or some other sensationalist title). Other financial books just regurgitate information that can be found for free on the internet.
I'm not sure it is possible to identify a useful book from just the 1st few pages!
I find reading reviews about the book (on say Amazon) helpful. It is also useful to test out ideas explained to see if they really work. If they don't work then the book is probably junk.