How to change URL alias when importing books? I am importing some books and would like the url to reflect the category name i.e. sample.com/fishing-books/booktitle where fishing-books is the product category.  

There is a field on the URL alias page (patterns): Default path pattern (which applies to all content types with blank patterns below) which I'm trying to make it work, but I haven't been successful. I want something like [cat]/[node:title], but it doesn't work.
Have you created a vocabulary for these books?

If not:


Create a vocabulary, e.g. "books_category" 
Add to your content type field, e.g. "books_category" (field type: Term reference), choosing the vocabulary you previously created as reference


After that, click at replacement patterns (admin/config/search/path/patterns); choose group "Tokens related to individual content items," or "nodes"; you will find a group of patterns related to your "books_category" field. 

I assume you installed the Pathauto module.