I don't know about a manual; but there is a very good and comprehensive series of free videos at labminutes.com.
http://labminutes.com/video/sec/ASA%20FirePower
You might also have a look at this document:
http://www.cisco.com/c/en/us/support/docs/security/firesight-management-center/118595-configure-firesight-00.html
It's much briefer but it will get you up and running quickly.