Virtual or Multiple sites w IIs Server

are you referring to using multiple sites with one IP,or multiple sites with multiple ips? either way it's fairly simple.

in IIS once you create a site, you right click on it, select properties, and under Web Site Identification, you click on Advanced next to the IP address. in the popup, under Multiple identies for this site, you select Add (or Edit the existing indentity). in the nex tpop up, select the IP address, the port, and the most important part, the host header name. the host header name will be the host name that HTTP 1.1 compliant browsers send in their request to the server. The IIS server will then read the host header name and send it to the correct site based on this name.

the draw back to using this method is if a non-HTTP 1.1 compliant browser tries to access this, it won't send the headers and IIS won't be able to direct to correct site, and you will get the default site or an error. to fix this you have to create pseudo-headers using cookies or munging (munging is embedding the host name into the url for the site). this is a bit more complex, but you shuld be able to find instructions for this on the resource kit. if you're not worried about pre-HTTP 1.1 browsers than don't bother

as far as multiple sites with multiple IPs, what you need to do is bind additional IP addresses to your NIC adapter. open up network and dialup connections, right click on the appropriate connection, select properties, right click on TCP/IP select properties, click on advanced, click on Add under IP addresses, and add the new IP and subnet.

provided the IP is valid and not used, the next time you start open your IIS manager, the new IP address will be available in the list of IP addresses for IIS to use (follow the initial step above and you'll see what i mean). if you follow the steps above (minus adding a host header name), you can also have multiple IPs for one site.

hope that helps.