how to enable temporal database capability in mysql.?
Add a from_date field, and a nullable to_date field
expand your primary key to include from_date
keep everything in UTC
consider using PostgreSQL as there is a temporal extension for preventing overlapping time periods. 


Here is the book from "THE" temporal db guy (Snodgrass):

http://www.cs.arizona.edu/~rts/tdbbook.pdf

Also try Chapter 4 of Celko's Smarties book