Hi there
For Internet access you could ensure that 1) The router blocks certain sites,
2) his computer only gets Internet access via another machine (like a server or whatever) and this machine can easily control the Internet access.
Set it up so his I.E (or whatever browser he's using) has to use a Proxy server -- this sounds complex but isn't actually too difficult to do -- this is how a lot of companies control Internet access.
Just search Google on Setting up a Home proxy server - there's too many links to paste one here -
However the easiest method is to use a program (Free) called Winproxy .
Instructions here
WinProxy :: Installing and configuring WinProxy
Once you've got this working you could get the program (server) to send you an email or message immediately he logs on to something he shouldn't be doing.
You can even set it up that Internet access is only allowed at certain times and for certain periods.
Actually blocking Google is IMO a bad idea as this site is probably a great help for people when doing homework -- I just wish I'd had a tool like google when I was 15 !!.
Your server can still block the sites if google re-directs to a site you don't want him access to.
The server will send this type of message (you can customize it to whatever you want BTW)
enc screenshot
Cheers
jimbo