go here [url:1q6o79t2]http://sourceforge.net/project/showfiles.php?group_id=196195[/url:1q6o79t2], go to the postbooks databases section, then find the section that matches the version of postbooks you have installed exactly.  download the intall.txt file and the qickstart.back file.  you may have to read some of the pgadmin documentation to be able to accurately follow the install instructions.  basically, you want to replace the 'demo' database with the 'quick start' database and customize it to your company.
Please visit: http://www.xtuple.org/phpBB3/viewtopic.php?f=&t=3513&p=0 for the changed document