to know internet usage and bandwith
 

We have Ubuntu server installed and others are windows clients. i want to monitor websites visited, software installed that type of information of windows client from ubuntu server,someone suggested to use squid proxy but i dont know how to install and route the traffic from squid proxy. If anyone can suggest anything on that..Thanx

I don't think that "websites visited" and "software installed" would ever be grouped into a single "type" of information to record. Squid is an HTTP proxy, so you can monitor web traffic using that, certainly. Not sure why you're saying you don't know how to install it though, as there are thousands and thousands of pages online about how to run it.