i think u talk about importing database backup file that come with soruce (***.sql)
if yes :
after u install Appatch,Appserv or what server u use :
1-go to:

or go:

and then search for phpmyadmin link ,and click it.
2-enter ur database user and password ,click ok (the password u enterwhen setup server [and user at most is : root] if u don't change while setup)
3- u'll fin at left block there r button called "SQL" or Query windows click it and it will open new window
4-u 'll find 3tabs above click NO#2 "Import file"
5- then choose file(***.sql) from ur pc and click (go) wait it take some time depend on ur pc and Size of file
6-after finishing back to"phpmyadmin page and at left u'll find drop list that contain all database ,click ur database and then u'll find tables
7-when u want add new account ,click on icon left Account's table at left block (or click on table name then click Browse ).
then u'll find button above called "Insert" click it and enter info then at bottom u'll find button "Go" click it and u r done