I am in search of the best tool(s) to use for network discovery. I would need to collect and store in some format (a database) information about a site, the computers, network, accessories, hardware, software and topology including "properties" for each of them such as the "dell service tag" or computer name, or location. and the history of each of them (repair).

If I go to a new company I'd like to be able to map out the whole network & place this info in a database with the least amount of manual data entry possible. I'd like top grade software that will find windows machines (xp, vista, server), Linux machines, routers (cisco, etc), Maybe even printers or the number or monitors connected to the machine.

I think I should add that this would be used at clients sites so I wouldn't have user names and passwords already setup on any machines.

Thanks in advanced.