slots are run by computers and winning is solely random. Anyone who writes such a book is full of gibberish. There are articles available explaining how slots operate, and how they are ordered by casinos at a preset payback percentage. In Nevada, the payback ratio range is set by the State gambling commission.
I used to work for a casino and Patty Bee is generally right. There is no betting strategy or method of pushing the buttons that will give you an advantage. Machines near the front doors or other places where the casino wants to lure guests in may be set to pay out more often but with smaller jackpots. It gives the illusion of winning. That won't really help you come out ahead though since the payout percentage is still pretty much the same as all the rest of the machines.