Hey Helpm3,
I have done this for few people already...also concern parents of teenage kids.
there are couple of ways of monitoring the computer activity...one is live monitoring and the other is after the fact......live monitoring could be done through the following software
http://www.radmin.com/
I'm sure there are tones of these software out there but I'm very familiar with this one...you could install in on the target PC and hid the service ICON and then run the same software on different computer and watch exactly what appear on the other screen......if you want to use this software PLEASE read the instruction first.....it's simple and yet very powerful.
The second option "after the fact" is spying option.....you could simply install spying software on the target PC......spying software are capable of recording screen shots, key stroke and much more.......
http://www.e-spy-software.com/spy_software.htm
the spy software runs in stealth mode and it can save the screen shot in network computer or even email it and if you want to get fancy....you could have the spy software upload the screen shot to FTP server (if you have access to one.
Hope this helps.
Cheers