g1smd - 7:47 am on Sep 30, 2012 (gmt 0)
Use example.com in this forum to suppress URL auto-linking.
It creates very little server load.
href="www.example.com/book/name/motor_car" from the pages of your site and add a RewriteRule to match those requests to the actual internal filepath that will serve the content.
As this is a question that has been asked several times per week for the last decade here, there are several thousand prior threads with example code. Use these for ideas, test your code, then post here about any specific problems you are having.
Do use extensionless URLs. Avoid all underscores and spaces in URLs. Strip out any "special characters" as encoded URLs are not easy to read.