How to sell the right product

In my line of work I have to be able to give customers exactly what they're looking for or at least be able to suggest products that they would enjoy.  I work at a book store and we have to be able to give assistance to customers even if that means spending a half an hour just to track down the book they are talking about.  The best part is when you get customers who come in saying that they don't know the title or author of the book, but they remember that the color of the book was blue.  With just that much information it is very hard to pin point the book they are talking about, but yet they expect us to find it with our computer system which is very difficult to do.  We also get customers who want suggestions on what to read and we have to be able to give them the right suggestions and meet their needs in order to get the sale.  Marketing is a big part of my job.  We set up displays in order to attract the customers eyes, we also set up displays in front of the cash register because that is where a lot of people do their impulsive buys whether it be magazines, toys, or more books.