How do I find the location of a file that starts a program at boot time?

[Bob]

Linux newbe.  I installed the NUT monitor from the Ubunut Software Center.  The
Ubuntu Software Center lists version 2.6.4-2.3ubuntu2 but when I look at the
NUT Monitor ABOUT the program has version 1.3!

I am replacing an old computer running OS/2 as a file and print server for my
home LAN
with a new computer running Ubuntu.  I moved the UPS serial connection from the
old computer to the new one but am having problems getting UPS logging to work.
When I boot the computer UPSLOG starts but is not finding the UPS so the log is
full of useless data.  How do I find which file starts the UPSLOG?

As a side problem it appears that the UPSLOG does not operate as the
documentation describes.  I added a file for the logrotate program which does
rotate the log but other than that does not appear to work.  When the logrotate
program runs the logger stops when it gets the "kill -HUP" signal instead of
continuing with the new log file.

I have read the readme file but there is not much about installation.  I have
looked at some documentation on the internet trying to get this installed but
the documentation does not match the configuration files I have on my system. 
Anyone know where I can find documentation that matches the version I have?

-- 
Robert Blair