Question: I would like to know how to find IP address and/or a MAC addresses of some popular web sites or servers servers.
For example: Google, Hotmail , Yahoo, etc.

Answer: 
Try an online `nslookup` service like <http://www.kloth.net/services/nslookup.php>.

For example, enter "maps.google.com" in the "Domain:" box and hit return.

You can only see the MAC address of machines on your local (sub)network, so you're out of luck there (although I *can* think of some reasons that that would be interesting :) ).
To get the IP use `nslookup` on windows or `dig` on Linux

You cannot query the MAC address as this is only known to the next switch/router in the companies infrastructure. 
Also the MAC address is specific to one single network interface whereas from the network-topology side of view behind one IP there can be hundrets of servers due to NAT/Load Balancing.