I'm not really sure if you are asking for the official sites,
Here are the one's I know about
:
http://www.princeofwales.gov.uk/
http://www.althorp-house.co.uk/
http://www.princemichael.org.uk/
I see that it looks like you are looking for links. I use Gererldine's or Netty's links - they are the best on the net.
Here is the link to Gereldine's Links:
http://royal.start4all.com/