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.
in a terminal (a command prompt if you are on Windows) to get the resolved IP address printed. This is the easiest way I use in practice, and it is more or less universal.
The MAC address is not printed, and I cannot imagine why it would be interesting. You probably only want the IP address.
EDIT: Adding my comment about MAC addresses:
Try an online
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
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.